D_s* -> D_s γ
from D_s^* D_s @ 4160 MeV

Efficiency for h+e+nu event to pass

SL Mode	ε
φ e ν	13.9832% (28.479%)
η e ν	22.2515% (56.3814%)
η' e ν	4.02662% (23.3473%)
f0 e ν	22.1258% (42.5496%)
Ks e ν	38.8379% (56.6068%)
K* e ν	27.3336% (41.0599%)

Efficiency for h+e+nu event to pass, allowing double counts

SL Mode	ε
φ e ν	13.9864%
η e ν	27.3824%
η' e ν	4.21797%
f0 e ν	22.1258%
Ks e ν	38.8379%
K* e ν	27.3336%

Efficiency for h+e+nu event to pass, h+e correctly found

SL Mode	ε
φ e ν	13.9606%
η e ν	13.2209%
η' e ν	3.70216%
f0 e ν	21.9564%
Ks e ν	38.3792%
K* e ν	27.1476%

K*: Tighter K* (Full Kaon PID, HF > .5, 63.7 MeV mass cut):
D_s true, SL true: 730 → 567
D_s false, SL true: 177 → 146
D_s true, SL false: 704 → 159
D_s false, SL false: 5,681 → 2,091

All SL modes: In 20X charm only sample
"True SL" defined as the event having the proper D_s → h e ν

Mode	True Ds, True SL	False Ds, True SL	True Ds, False SL	False Ds, False SL
φ e ν	4,326	821	83	263
f0 e ν
η e ν	9,727	1,062	1,421	6,345
Ks e ν
K*0 e ν
η' e ν	632	302	174	627

By hadron mode plots:

φ e ν
η e ν
η' e ν

All SL modes: In 20X charm only sample
(continuum adds a handful of non-peaking events; worst cont is in K*, where it adds another 40% to the False/False column)

Mode	True Ds, True SL	False Ds, True SL	True Ds, False SL	False Ds, False SL
φ e ν	4,319	608	90	476
f0 e ν	1,037	119	58	1,341
η e ν	6,692	563	4,451	6,844
Ks e ν	592	136	3,285	4,433
K*0 e ν	730	177	704	5,681
η' e ν	468	138	338	791

Preliminary plots:

φ e ν
f₀ e ν
η e ν
η' e ν
K_s e ν
K* e ν

Results of D_s tagging

Graphical representation of fit results

MC/data comparison

D⁺ systematic, fixing BG and N₁

D⁺ systematic, fixing BG

D⁺ systematic

φeν data results

Here are the results from my initial data running. Currently, I have not applied the correction for electron efficiency (a function of electron momentum). I also have not made an f₀ correction.

D_s Tags
D_s tags

Tagging results

Mode	Standard	Relative σ	Relative Norm	Signal histogram
Ks K	6241.33 +/- 102.839	6221.43 +/- 126.131	6459.55 +/- 130.526	6233.28 +/- 95.5294
K K π	27367.1 +/- 252.175	26730.6 +/- 311.244	28166 +/- 428.888	27494.6 +/- 227.137
Ks K π0	2110.22 +/- 182.966	2096.29 +/- 237.92	2382.98 +/- 322.239	2002.67 +/- 130.734
Ks Ks π	1127.55 +/- 78.1736	1114.31 +/- 79.6138	1187.1 +/- 141.264	1156.88 +/- 63.7314
K K π π0	7353.29 +/- 493.526	11071.8 +/- 2489.98	7337.79 +/- 516.191	7220.51 +/- 220.325
Ks K+ π π	1838.97 +/- 122.186	1837.48 +/- 151.432	1914.71 +/- 259.649	1838.97 +/- 99.6395
Ks K- π π	3402.95 +/- 101.677	3249.39 +/- 97.8562	3500.14 +/- 200.132	3447.93 +/- 90.0461
π π π	6449.1 +/- 382.831	6339.83 +/- 658.05	6305.09 +/- 763.74	6198.12 +/- 208.134
π η	3804.69 +/- 211.189	3953.61 +/- 468.853	3715.09 +/- 366.228	3496.85 +/- 133.296
π π0 η	18738.4 +/- 4340.14	21737.2 +/- 9015.48	18184.4 +/- 1759.08	6635.45 +/- 416.158
π η'	2372.66 +/- 67.3958	2373.11 +/- 90.873	2465.63 +/- 82.4825	2282.93 +/- 59.3224
π π0 η'	1233.79 +/- 149.431	1140.07 +/- 133.643	1175.13 +/- 142.3	1194.55 +/- 97.2007
π η' -> ρ γ	4889.31 +/- 441.745	4594.77 +/- 391.91	4594.55 +/- 392.083	4523.1 +/- 210.174

Semileptonic side
D_s mass after φ and e requirement

Branching ratio results (not x10^-2, so 0.017 is a BR of 1.7%).

Mode (** = fit problems)	BR, standard	BR, relative σ systematic	BR, relative norm systematic	BR, histogram + BG fit
Ks K	0.0170193 ± 0.00503084	0.0170371 ± 0.00503545	0.0183985 ± 0.00510749	0.0176737 ± 0.00508424
K K π	0.0178153 ± 0.0023169	0.0178647 ± 0.00232476	0.0177085 ± 0.00229445	0.0178982 ± 0.00230558
Ks K π0 **	0.0112323 ± 0.00900541	0.0115971 ± 0.00911743	0.0129534 ± 0.0094303	0.0113234 ± 0.00968994
Ks Ks π **	0.0323524 ± 0.0152126	0.0302721 ± 0.0155158	0.0333538 ± 0.016582	0.032252 ± 0.0319117
K K π π0	0.0101963 ± 0.00433259	0.00835533 ± 0.00404922	0.0116405 ± 0.00484225	0.0105121 ± 0.00441161
Ks K+ π π **	0.0669433 ± 0.00464113	0.0669046 ± 0.0251704	0.068353 ± 0.0267403	0.0695637 ± 0.0131893
Ks K- π π	0.0191348 ± 0.00698998	0.018731 ± 0.0070293	0.0190645 ± 0.00698258	0.0192246 ± 0.00688057
π π π **	0.025766 ± 0.00706181	0.0255234 ± 0.00633806	0.0250675 ± 0.00701916	0.0261945 ± 0.00659726
π η **	0.0329815 ± 0.00214763	0.0341128 ± 0.0146555	0.0312649 ± 0.01297	0.0295507 ± 0.0028114
π π0 η	0.0142413 ± 0.00509959	0.0174805 ± 0.00845862	0.0144149 ± 0.00417852	0.0333673 ± 0.00898526
π η'	0.0343023 ± 0.0190698	0.0342821 ± 0.00169347	0.0367947 ± 0.020655	0.0315622 ± 0.00109151
π π0 η'	0.00976488 ± 0.00869826	0.0112979 ± 0.00919167	0.0090619 ± 0.0096372	0.142967 ± 0.0118375
π η' -> ρ γ	0.0171178 ± 0.00645429	0.0118022 ± 0.0050533	0.0118028 ± 0.00505364	0.0185034 ± 0.00691834
Total	0.0253156 +/- 0.00121455	0.0245545 +/- 0.00114207	0.0168775 +/- 0.00150159	0.0283826 +/- 0.000861954
Clean modes	0.0237064 +/- 0.00138851	0.0259682 +/- 0.00122748	0.0178499 +/- 0.00182721	0.0279576 +/- 0.000888392

φ mass systematic

f₀ part of systematic
The errors didn't seem to progress naturally as the f₀ mass shifted, so I generated some more MC to look into it. It looks like the generator changes when the mass central value passes the kinematic threshold.

Systematic error plots, excluding f₀ mass over KK threshold.
    Optimal φ mass cut: ~20 MeV on low side, 30 MeV on high side (maximum allowed)
Systematic error plots, including one f₀ mass over KK threshold (990 MeV).
    Optimal φ mass cut: ~16 MeV on low side, 30 MeV on high side (maximum allowed)

φ mass systematic

Two components:

• Data/MC difference (pushes to wider cut): Fit MC with gaussian smear (width and mass) to the inclusive φ data, taking the BG as given.
  Example fits for the HF < .5 sample (pg. 6-55 are different smears).
  Result: Very low systematic across all cut ranges; about .1-.2% for good tracks, and about .5% for HF < .5 tracks (need better plot with Χ² vs. ε for each cut)
• f₀ leaking in (pushes to lower cut): Generate signal MC with different f₀ widths and masses, then estimate amount of f₀eν relative to φeν for each cut. Systematic is roughly doubled thanks to adding in quadrature with imprecise BR(f₀->KK) and BR(D_s->f₀eν). This gives a correction to the φeν branching ratio and a tradeoff between the systematic effect and the statistical loss (pg 16-18 are the correction to φeν amount due to the presence of f₀eν, pg 19-21 are the effects on my total error for statistics and systematics across different cut ranges).
  Result: Need to try a few other cut options, but 12 MeV seems to be a balance if the BR(D_s->f₀eν) is about 1/7th that of φ. This increases the final error by about 1% (that is, after accounting for pythagorean addition, the error goes from ~7% to ~8%).

φ mass systematic

Comparison of MC and data for inclusive φ

Assorted plots for data/MC comparison

The bottom line:

• It looks like the low M_KK background (with a tail across the entire spectrum) is from three electrons (positrons), two of which are called K. These events are presumably from Bhabhas (e.g. radiative bhabha, one e gets picked up, and the photon pair produces?).
• Charm + continuum looks like it can reasonable model data if I make a cos(θ) cut.
  This is bothersome for my systematic check, but I don't have a better solution.
  Since the shape of the φ is dominated by the Breit-Wigner (really, the threshold equivalent function), the resolution for "good" tracks can't make a huge difference -- I'm really interested in the marginal tracks (.1 < HF < .5, certainly, but do I also need to know about the low angle tracks?).
• My next task is to check the φ mass for Good HF (>.5) and Poor HF (<.5) in Data & MC, then use MC's background to deduct from data. I'm not sure how I'll handle the leftover bhabha part of the background (e.g. harder cos(θ) cut? Come up with an actual model for the bhabhas?)

Side note: Kaon track momentum when I originally imposed 1200 MeV momentum cut (I can't reproduce this, perhaps due to some cut I imposed midway through my investigation that eliminates it).

D⁺ → K_s e ν

Final(?) results:
Corrected bug in relative σ/normalization, widened recoil mass (now 1980 MeV - 2090 MeV), and allowed multiple candidates (really only an issue for π⁰ modes).

Tagging results

Mode	Standard	Relative σ	Relative Norm	Signal histogram
K π π	39760.1 +/- 254.389	38775.8 +/- 305.244	41444.8 +/- 380.031	39050.9 +/- 234.368
K K π	3301.96 +/- 153.097	3228.01 +/- 205.018	3520.19 +/- 314.902	3307.21 +/- 123.03
Ks π	5201.3 +/- 102.867	5142.36 +/- 117.36	5700.12 +/- 152.461	5116.34 +/- 90.9321
Ks K	919.425 +/- 61.1171	897.534 +/- 61.9776	907.678 +/- 121.11	914.009 +/- 50.6835
Ks π π0	12422.5 +/- 507.899	12741.9 +/- 804.559	12273.7 +/- 615.734	10554.2 +/- 268.012
K π π π0	13480.6 +/- 504.819	13463.9 +/- 1028.01	13411.7 +/- 718.848	11954.8 +/- 303.89

Results of Tag + K_s + e (Note: BR is relative to decay.dec, so normalized to 1.0)

Mode	BR, standard	BR, relative σ systematic	BR, relative norm systematic	BR, histogram + BG fit
K π π	0.960178 ± 0.0547536	0.962902 ± 0.0550278	0.958556 ± 0.0542575	0.958811 ± 0.0545884
K K π	1.28787 ± 0.212309	1.28927 ± 0.219307	1.32586 ± 0.237722	1.2932 ± 0.208433
Ks π	0.765465 ± 0.119704	0.765625 ± 0.119846	0.798116 ± 0.120177	0.762777 ± 0.118673
Ks K	0.529316 ± 0.269319	0.537267 ± 0.271946	0.53357 ± 0.277546	0.523997 ± 0.270721
Ks π π0	0.773592 ± 0.112401	0.797047 ± 0.12102	0.871113 ± 0.125592	0.774163 ± 0.114627
K π π π0	1.03828 ± 0.118925	1.03777 ± 0.137486	1.03181 ± 0.124834	1.05598 ± 0.119763
Total	0.923677 +/- 0.0411981	0.926767 +/- 0.0424337	0.939216 +/- 0.0419896	0.92582 +/- 0.0412015

Plots:

• Tagging
• D⁺ with K_s and e fit

D⁺ → K_s e ν

The whole enchilada:
Aside: I have some factor ~2 problem with my efficiency vs. naive efficiency (93% K_s [Stroiney], ~70-80% for e [need momentum dist]). Whatever is causing this loss (code bug, real physics) seems consistent everywhere, so I plowed on, but I still need to investigate.

Tagging results

Mode	Standard	Relative σ	Relative Norm	Signal histogram
K π π	25528.6 +/- 183.077	25165.3 +/- 205.232	26151.6 +/- 215.946	25413.2 +/- 176.269
K K π	2190.76 +/- 90.0556	2128.17 +/- 100.067	2172.24 +/- 161.315	2192.51 +/- 76.3626
Ks π	3301.7 +/- 70.262	3292.81 +/- 77.7828	3505.75 +/- 88.5134	3284.46 +/- 66.2669
Ks K	550.27 +/- 36.3874	533.605 +/- 35.5417	533.034 +/- 34.8429	557.881 +/- 32.9193
Ks π π0	7116.31 +/- 233.378	7346.47 +/- 403.714	7003.62 +/- 244.923	6751.3 +/- 154.772
K π π π0	7975.99 +/- 247.195	8055.49 +/- 452.868	7939.46 +/- 342.447	7363.27 +/- 167.18

Results of Tag + K_s + e (Note: BR is relative to decay.dec, so normalized to 1.0)

Mode	BR, standard	BR, relative σ systematic	BR, relative norm systematic	BR, histogram + BG fit
K π π	0.970088 ± 0.0914927	0.986798 ± 0.0945359	0.897764 ± 0.0859972	0.964515 ± 0.0912745
K K π	1.23299 ± 0.28806	1.25422 ± 0.297533	1.13149 ± 0.277202	1.25782 ± 0.289498
Ks π	0.750217 ± 0.174484	0.737667 ± 0.17309	0.669151 ± 0.156949	0.752341 ± 0.174153
Ks K	0.992419 ± 0.566742	1.02793 ± 0.592311	0.932429 ± 0.541348	1.01638 ± 0.57869
Ks π π0	1.09744 ± 0.177517	1.57588 ± 0.255851	0.973311 ± 0.164084	1.08442 ± 0.178387
K π π π0	1.03257 ± 0.158004	1.32159 ± 0.208054	0.908545 ± 0.145077	1.05117 ± 0.162692
Total	0.980786 +/- 0.0646492	1.04522 +/- 0.0711034	0.887643 +/- 0.0600957	0.980121 +/- 0.0649394

Some components:

• Tagging
• K_s BG fit
• D⁺ with K_s and e fit

D⁺ → K_s e ν

Data superimposed on charm+cont for wide (± 30 MeV only) K_s cut as in D⁺ semileptonic CBX. (page 1-6 is only MC, 7-12 is MC on Data).
Note: Roughly half of all reconstructed D⁺ are true but are not from K_s e ν events. The K_s is typically incorrect in these events.
Data superimposed on charm+cont for my tighter (± 6.3 MeV; flight significance > 4) K_s cut as in D⁺ semileptonic CBX. (again, page 1-6 is only MC, 7-12 is MC on Data).
Note: Now ~10% of all reconstructed D⁺ are true but are not from K_s e ν events. The K_s is typically incorrect in these events as well.

D_s → φ e ν

#1 - Overlay data/MC in D⁺
     Note: Prior plots did actually have + and - charge (title was incorrect), so there was only a factor ~3x more data
The bottom line: There is a distinctive peak in all modes without requiring an electron. The electron requirement kills continuum, but there's still non-trivial combinatoric background (and efficiency is less than would be naively guessed; an electron momentum plot rises near low momentum, where the efficiency dies off).
Plots with no electron
Plots requiring an electron

#2a & b - Difference in σ₂/σ₁ ratio and tag counts when allowed to float in D⁺
The bottom line: The free floating relative width can vary a lot while not changing the D⁺ counts much (maximum of ~4% change in tag counts with ratio changes from 15%-47%). Statistical error in the relative width ratio is large relative to the central value.

Mode	σ2/σ1 fixed (from signal MC)	σ2/σ1 floating (from data)	Ratio free/floating relative widths	Number D+/- tags fixed (from data)	Number D+/- tags floating (from data)	Ratio free/floating D+/- counts
K π π	2.81082	1.9727	0.701823 +/- 0.0191459	25031.2	24669.4	0.985543 +/- 0.00715446
K K π	3.43956	2.48592	0.722743 +/- 0.600163	2229.96	2184.21	0.979487 +/- 0.0412519
Ks π	2.99899	2.64275	0.881212 +/- 0.222868	3263.23	3239.16	0.992624 +/- 0.0218981
Ks K	2.61455	1.37415	0.525579 +/- 0.394008	572.184	552.479	0.965563 +/- 0.06477
Ks π π0	1.84049	2.12884	1.15667 +/- 0.15022	7262.71	7566.11	1.04178 +/- 0.0260745
K π π π0	1.72176	1.71451	0.995789 +/- 0.181718	7918.68	7910.62	0.998982 +/- 0.0257993

#2c & d - Difference in N₂/N₁ ratio and tag counts when allowed to float in D⁺
The bottom line: Like the relative width, the free floating relative normalization can vary a lot while not changing the D⁺ counts much (maximum of ~5% change in tag counts with ratio changes from 2x-3x). Statistical error in the relative width ratio is even larger relative to the central value than for the relative widths.

Mode	N2/N1 fixed (from signal MC)	N2/N1 floating (from data)	Ratio free/floating relative widths	Number D+/- tags fixed (from data)	Number D+/- tags floating (from data)	Ratio free/floating D+/- counts
K π π	2.39919	7.12134	2.96822 +/- 0.324838	25031.2	24475.8	0.977809 +/- 0.00709831
K K π	0.10092	0.164719	1.63217 +/- 1.44502	2229.96	2290.94	1.02735 +/- 0.0432677
Ks π	0.0885686	0.234488	2.64753 +/- 0.751772	3263.23	3434.5	1.05249 +/- 0.0232188
Ks K	0.125173	7.34402e-10	5.86708e-09 +/- 1.26035	572.184	550.233	0.961638 +/- 0.0645067
Ks π π0	0.069141	0.141297	2.04361 +/- 2.04703	7262.71	7137.32	0.982734 +/- 0.0245968
K π π π0	0.0288083	0.0184386	0.640044 +/- 0.843693	7918.68	7825.17	0.988191 +/- 0.0255206

#2e - Difference in D_s branching ratio (20x MC).
The bottom line: The systematic effect is less than (but comparable to) the overestimation of the fitting procedure as a whole (which is essentially due to the ~3% f₀(980) contamination). When scaled down 20x, the statistial error should widen to be ~7%, while the systematic should stay at about ~2.5% for the BR.

Mode	BR from fit	BR Syst	BR True
KsK	2.46	2.47	2.41
KKπ	2.17	2.18	2.05
KsKπ0	2.66	2.69	2.50
KsKsπ	2.21	2.21	2.14
KKππ0	2.07	2.07	1.95
KsK+ππ	2.77	2.77	2.63
KsK-ππ	2.23	2.23	2.15
πππ	2.30	2.31	2.20
πη	2.49	2.54	2.32
ππ0η	2.15	2.40	2.46
πη',η'->ππη	2.52	2.51	2.33
ππ0η',η'ππη	3.63	3.74	2.06
πη',η'ργ	2.02	2.13	1.94
Total	2.25	2.30	2.17

• Duplicate Onyisi for D_s selection (modifying for 6 distinct modes):
  • Standard DTag cuts on daughters (K, π, π⁰)
  • Require recoil mass to be above a certain value (either 2.051 GeV or ~2.100 GeV, by mode)
  • Choose best candidate (for each charge) by recoil mass (closest to D_s*: 2.112 GeV)
  • Particular mode cuts to smooth background (e.g. no Kπ combination forms a D⁰ mass in KKπ)
• Fit the MC truth-tagged D_s mass with a particular function for the signal part: Double Gaussian (K_sK, KKπ, K_sK_sπ, K_sK⁺ππ, K_sK^-ππ, πη') or Gaussian + Crystal Ball (K_sKπ⁰, KKππ⁰, πππ, πη, ππ⁰η, ππ⁰η', πη'->ργ). Functions are same as Peter's, when applicable.
• Fit the reconstructed D_s shape, floating only overall normalization, mean*, and overall width (fixing relative normalization, relative width, and crystal ball power law). Background shape is linear except in modes with a noticeable curvature (KKππ⁰, πππ, ππ⁰η, πη'->ργ)

Mode	Fit estimate	True counts	# σ
KsK	5946.26 +/- 103.745	5701	2.36408
KKπ	25220.8 +/- 237.362	25658	-1.84194
KsKπ0	1738.45 +/- 130.992	1875	-1.04245
KsKsπ	1162.66 +/- 69.7679	1051	1.60044
KKππ0	7822.95 +/- 400.327	6932	2.22556
KsK+ππ	1787.96 +/- 106.753	1719	0.646014
KsK-ππ	3297.71 +/- 93.2123	3252	0.490333
πππ	5569.77 +/- 305.815	6185	-2.01175
πη	2994.76 +/- 173.338	3237	-1.39751
ππ0η	6842.96 +/- 764.267	7624	-1.02195
πη',η'→ππη	2216.71 +/- 66.2548	2168	0.735184
ππ0η',η'→ππη	536.281 +/- 70.4486	813	-3.92796
πη',η'→ργ	4378.11 +/- 262.416	4766	-1.47816

1. Tested fitting functions by running on generic MC. Sees Χ² of 28.7/9. The (mostly) overcounts are comparable to that from the systematic on the BG shape, so he doesn't try to correct for the overcount. When scaling to data-size, he expects .6σ issues. Assuming the overcount is a constant %, it would be 1.2σ for me on the number of tags, but it should cancel for the branching ratio.
2. Checked sample consistency by counting tags in each dataset (d39, d40, and d41) in addition to the total. They were consistent between datasets (slightly too consistent, if anything).
3. Checked charge asymmetry (plus vs. minus D_s). Consistent within errors.
4. Daughter particle reconstruction: .3% per charged track, .6% per kaon, 1.9% per K_s, 2% per π⁰, and 4% per η/η' (with π⁰ and η corrections of -3.9% and -5.7%, respectively). Tracking: CBX 06-29b, K_s: CBX 07-05 (with mass cut correction), π⁰: CBX 05-07, η from ψ' decays with higher uncertainty due to momentum adjustment. Other than η, systematics are from 4170 MeV D⁰/D⁺ studies. I use the same tight K_s mass cut as Peter for BG suppression (6.3 MeV -- 1.575σ).
5. K_s and η mode uncertainties. The MC (even regenerated) has K_s -> ππ as 68.61%, while the PDG value is now (69.20 ± 0.05)%. Peter corrects his efficiencies by the ratio and gives a relative uncertainty of 0.07% for K_s modes. The η and η' have relative uncertainties on their PDG BR of 0.7% and 3.1%, respectively. η' -> ρ γ, which Peter doesn't do, has a relative uncertainty of 3.1% also)
6. PID efficiency correction and systematic for π and K (by momentum). The correction ranges from 0 to -3.7%, by mode (highest correction when slow K -- KKπ, KKππ⁰), and systematics from .2% to 1.4%, by mode (highest for slow K).
7. By mode systematics and corrections due to resonant substructure. No systematic for two-body modes, 1.5% systematic for KKπ (φπ lower efficiency than K*K), and so on. Most modes wind up with a ~2% systematic. KKππ⁰ also has a correction of 3.3% to its efficiency since the relative amount of K*X to φX is higher in data than MC.
8. D_s* -> D_sπ⁰ have higher efficiency when the recoil mass cut has to be tight for BG rejection. The effect is only ~.15% in those modes, though.
9. Two fit function systematics. Peter normally fixes the nominal width (and relative width/normalization) in his fit; for one systematic check, he lets the width float. For the other, he switches his linear BG with a quadratic, and he switches the quadratics with a linear BG. The width systematic has four modes at ~1%, one mode at ~2%, and three modes with 4-10%. The BG systematic has three modes at ~1%, with the rest from 2-8%. For me, this will presumably be replaced by my D⁺ systematic study.
10. ISR. The tight recoil mass cut eats into the kinematic range a little bit, so he takes a .8% systematic on such modes due to ISR. This comes from the ratio of events kept with a loose vs. tight cut in data compared to MC. I'm suspicious of this systematic because the recoil mass cut is a lower bound only, while ISR would raise the recoil mass (lower momentum).
11. A best candidate is chosen based on recoil mass. If there are more/less multiple candidates in data relative to MC, this could decrease the efficiency. The difference in multiple candidate rate between data and MC is fairly small, and assuming a worst-case random choice selection, the efficiency is .5% or smaller.
12. FSR. Peter turns off FSR and fits, seeing effects from .6% (K_sK) to 3.8% (πππ). He takes 30% of this gap as a systematic (so 1.15% for πππ is the largest).

D⁺ systematic check
Notion: Take modes similar to D_s modes and fit, letting one extra parameter float each time (relative width, relative normalization).

• Use six modes: Kππ, KKπ, K_sπ, K_sK, K_sππ⁰, Kπππ⁰
• Choose best candidate by recoil mass (D*^-: 2010.3 MeV). Also have by mode cuts as in D_s (e.g. Kπ not a D⁰).
• Fit truth-tagged MC to get signal shape parameters. Then fix all but overall normalization, mean*, and width, and fit data. Float relative width and fit again, using the difference in branching ratio as the systematic. Repeat for the relative normalization.

Effect on tags:

Ds Tag Mode	D+ ratio mode	Fit estimate	Systematic fit	True counts	# σ
Ks K	Kππ	5758.2 +/- 102.42	5634.08 (-2.15557%)	5689.55	0.670267
K K π	Kππ	25187.2 +/- 237.27	24684.7 (-1.99514%)	25694	-2.13609
Ks K π0	Ksππ0	1756.66 +/- 134.695	1816.8 (3.42325%)	1866.25	-0.813613
Ks Ks π	Ksπ	1142.25 +/- 70.7318	1134.84 (-0.648415%)	1080.9	0.867301
K K π π0	Kπππ0	6820.31 +/- 343.82	6810.53 (-0.143364%)	6827.85	-0.021943
Ks K+ π π	Ksπ	1749.57 +/- 107.688	1740.12 (-0.54013%)	1715.55	0.315906
Ks K- π π	Ksπ	3236.17 +/- 93.3729	3218.54 (-0.544896%)	3194.85	0.442561
π π π	Ksπ	5999.22 +/- 331.49	5850.13 (-2.48521%)	6177.2	-0.536909
π η	Ksππ0	2998.71 +/- 161.118	3105.49 (3.56088%)	3321	-2.00037
π π0 η	Ksππ0	9148.12 +/- 1361.18	8641.94 (-5.53317%)	7589.95	1.14472
π η'	Ksππ0	2143.53 +/- 66.307	2182.24 (1.80572%)	2106.75	0.55473
π π0 η'	Ksππ0	631.174 +/- 83.1444	646.91 (2.49313%)	866.45	-2.82973
π η' -> ρ γ	Ksππ0	4651.5 +/- 255.029	4647.79 (-0.0797164%)	4842	-0.746984

Effect on signal:

Mode	Fit estimate	Syst estimate	True counts	# σ
KsK	404.594 +/- 20.6156	397.037 (-1.86788%)	391	0.659415
KKπ	1559.78 +/- 40.7421	1535.3 (-1.56922%)	1501	1.44275
KsKπ0	133.246 +/- 14.2205	139.646 (4.80359%)	133	0.0172659
KsKsπ	72.2523 +/- 8.94567	71.7778 (-0.656856%)	66	0.698925
KKππ0	403.255 +/- 23.9062	402.785 (-0.116643%)	380	0.972757
KsK+ππ	138.429 +/- 12.244	137.433 (-0.719701%)	129	0.77012
KsK-ππ	206.199 +/- 14.8578	205.319 (-0.426752%)	196	0.686464
πππ	393.469 +/- 21.539	386.123 (-1.86716%)	389	0.207497
πη	213.362 +/- 17.4685	225.3 (5.59508%)	220	-0.379981
ππ0η	561.318 +/- 34.5604	592.415 (5.54003%)	533	0.819378
πη',η'→ππη	154.475 +/- 13.6559	156.341 (1.20775%)	140	1.05999
ππ0η',η'→ππη	65.5046 +/- 9.56044	69.1021 (5.49198%)	51	1.51715
πη',η'→ργ	268.81 +/- 19.4929	282.652 (5.14925%)	268	0.0415691
Total	4574.7 +/- 77.0111	4397	2.30741

// Add BR Relative normalization:

Mode	Signal MC (fixed) σ2/σ1	Data (float) σ2/σ1	float/fixed ratio
Kππ	2.40	7.12 ± 0.78	2.97
KKπ	0.10	0.16 ± 0.15	1.63**
Ksπ	0.089	0.23 ± 0.07	2.65
KsK	0.13	0.00 ± 0.16	0**
Ksππ0	0.069	0.14 ± 0.14	2.04**
Kπππ0	0.029	0.018 ± 0.024	0.64**

Effect on tags:

Mode	Fit estimate	Systematic fit	True counts	# σ
KsK	5758.2 +/- 102.42	6078.9 (5.56954%)	5689.55	0.670267
KKπ	25187.2 +/- 237.27	27368.2 (8.65921%)	25694	-2.13609
KsKπ0	1756.66 +/- 134.695	1786.19 (1.68078%)	1866.25	-0.813613
KsKsπ	1142.25 +/- 70.7318	1214.66 (6.3395%)	1080.9	0.867301
KKππ0	6820.31 +/- 343.82	6576.22 (-3.57877%)	6827.85	-0.021943
KsK+ππ	1749.57 +/- 107.688	1879.73 (7.4395%)	1715.55	0.315906
KsK-ππ	3236.17 +/- 93.3729	3493.15 (7.9407%)	3194.85	0.442561
πππ	5999.22 +/- 331.49	6745.32 (12.4366%)	6177.2	-0.536909
πη	2998.71 +/- 161.118	3068.07 (2.31324%)	3321	-2.00037
ππ0η	9148.12 +/- 1361.18	8875.12 (-2.98419%)	7589.95	1.14472
πη',η'→ππη	2143.53 +/- 66.307	2216.64 (3.41075%)	2106.75	0.55473
ππ0η',η'→ππη	631.174 +/- 83.1444	637.834 (1.05529%)	866.45	-2.82973
πη',η'→ργ	4651.5 +/- 255.029	4621.6 (-0.642665%)	4842	-0.746984

D_s → φ e ν

Tagging
My fit to the D_s tags, both charges.
The signal part of the fit compared to the MC truth tagged part.
Results, with errors

Mode	Fit estimate	True counts	# σ
KsK	5758.2 +/- 102.42	5689.55	0.670267
KKπ	25187.2 +/- 237.27	25694	-2.13608
KsKπ0	1756.67 +/- 134.695	1866.25	-0.813517
KsKsπ	1142.25 +/- 70.7318	1080.9	0.8673
KKππ0	6820.34 +/- 343.743	6827.85	-0.0218556
KsK+ππ	1749.57 +/- 107.688	1715.55	0.315906
KsK-ππ	3236.17 +/- 93.373	3194.85	0.442561
πππ	5999.22 +/- 331.381	6177.2	-0.537086
πη	2998.71 +/- 161.118	3321	-2.00037
ππ0η	9148.03 +/- 1374.03	7589.95	1.13394
πη',η'→ππη	2143.53 +/- 66.3072	2106.75	0.554728
ππ0η',η'→ππη	631.181 +/- 83.1534	866.45	-2.82934
πη',η'→ργ	4651.55 +/- 255.061	4842	-0.746674

Effect on signal:

Mode	Fit estimate	Syst low estimate	True counts	# σ
KsK	404.594 +/- 20.6156	433.338 (7.10436%)	391	0.659415
KKπ	1559.78 +/- 40.7421	1606.47 (2.99305%)	1501	1.44275
KsKπ0	133.246 +/- 14.2205	141.344 (6.07783%)	133	0.0172659
KsKsπ	72.2523 +/- 8.94567	75.2316 (4.12335%)	66	0.698925
KKππ0	403.255 +/- 23.9062	388.233 (-3.72526%)	380	0.972757
KsK+ππ	138.429 +/- 12.244	144.769 (4.57957%)	129	0.77012
KsK-ππ	206.199 +/- 14.8578	212.681 (3.14346%)	196	0.686464
πππ	393.469 +/- 21.539	423.656 (7.67191%)	389	0.207497
πη	213.362 +/- 17.4685	226.839 (6.31657%)	220	-0.379981
ππ0η	561.318 +/- 34.5604	548.857 (-2.22001%)	533	0.819378
πη',η'→ππη	154.475 +/- 13.6559	166.388 (7.71206%)	140	1.05999
ππ0η',η'→ππη	65.5046 +/- 9.56044	69.4591 (6.03688%)	51	1.51715
πη',η'→ργ	268.81 +/- 19.4929	267.47 (-0.498491%)	268	0.0415691
Total	4574.7 +/- 77.0111	4397	2.30741

D_s → φ e ν

Desperately trying to finalize tagging:

• Fit underestimates the amount of signal by ~2% in double gaussians, ~0.5% in crystal ball + gaussian in signal MC
  • Problem is that in fitting the large peak, the function undershoots the low D_s mass tail.
  • Maybe not as much of a problem in reconstructed MC? Don't know, broke code, still fixing.
• The only plots I haven't overwritten with garbage: reconstructed fit in 20x Charm + 5x Cont, re-weighted to match data size (displayed errors not meaningful!)

D → K l ν

Comparing with Prof. Hennessy:
I have been trying to compare the results from my code and Prof. Hennessy's code.
There were multiple discrepancies:

• We were running on different samples
• Candidate counting (me) vs. event counting (Prof. Hennessy)
• D mass different by .5 MeV (affected one event)
• Slight bug in Prof. Hennessy's track selection (hit ~2.5% of events)

D_s → φ e ν

Put together all fixes from last couple months (use regen MC + d47 + d48, π cut from K_s, π⁰ η fix) and did tag fitting in 20x MC.

Current fit procedure:

• Fit to the MC shape with gaussian + gaussian, or gaussian + crystal ball (depends on mode)
• Fix crystal ball power law (n, #σ when switch) from MC shape (fit has had problems when these float).
• Previously: Fix crystal ball and gaussian σs, mean, relative normalization; only let overall normalization float.
• Now: (still testing) Fix relative σ, relative normalization, let mean, absolute normalization, and absolute σ float. (Note: K_s and π⁰ η modes were the problems with this before)

D⁺ → K_s μ/e ν

Had problems with four files (d32_10x_J13, d32_10x_J17, d32_30x_J6, d32_30x_J52),
but finally was able to skim/run over all.
My D32 Kπ Tags: 7,148
Hennessy Tags: 6,812

My pass U Loose (after E_miss, 2 good and 0 bad tracks, proper charges): 5,293
Hennessy pass U Loose (same cuts?): 4,533

D_s → φ e ν

D⁺ MC matches up surprisingly well with D⁺ data (all from data 48).

D⁺ → K_s μ/e ν

Fixed code bug, now just have physics issues:

• Hennessy's U cut seems too tight -- constraining Beam - DTag = D?
• My lepton PID (μ vs. e) kills 75% of my Kμν events -- something must be up, but not sure what (killing 25% doesn't make much sense either...)

D_s → φ e ν

Working on D⁺ reconstruction resolution cross-check. I'm tracking down bugs in my plots.

D⁺ → K_s μ/e ν

Found problem with Generated counts: Wrong DECAY.DEC!

Broke my functions into jlib.h

Trying to replicate Kμν to make sure we're on the same page. I get segmentation faults when I extract photons for Kππ⁰ rejections -- haven't found the bug yet.

D_s → φ e ν

I made a p_π > 100 MeV for the K_s modes to get rid of peaking background (soft π swapping): Background D_s mass vs. Signal D_s mass

D⁺ → K_s μ/e ν

Redone K_s μ/e ν plots (cuts now in serial).

K_sμν
Note: ** = No extra tracks cut will be where K_s → π⁰ π⁰ is lost, so it is 69% at most.

Cut	Passing Ksμν	Passing Kseν	Passing BG	εKsμν
Generated	3245	3100	104882	100%
Have Kpipi   (BR 9.5%)	166	143	4236	5.11556%
No extra tracks**	83	62	1455	50%
Have Ks	78	50	474	93.9759%
Have a lepton	77	46	434	98.7179%
Charges match	77	46	433	100%
Reasonable Missing energy	77	46	413	100%
Reasonable Missing mass	75	41	123	97.4026%
No pi0s	70	39	42	93.3333%
No shower too large	61	36	34	87.1429%
Total extra energy O.K.	58	36	33	95.082%
Ks daughters PID	58	35	22	100%
Lepton PID	57	34	22	98.2759%
Ks flight signif O.K.	53	33	19	92.9825%

K_seν

Cut	Passing Kseν	Passing Ksμν	Passing BG	εKseν
Generated	3100	3245	105027	100%
Have Kpipi   (BR 9.5%)	143	166	4236	4.6129%
No extra tracks**	62	83	1455	43.3566%
Have Ks	50	78	474	80.6452%
Have a lepton	46	77	434	92%
Charges match	46	0	510	100%
Reasonable Missing energy	46	77	413	100%
Reasonable Missing mass	41	75	113	89.1304%
No pi0s	39	70	39	95.1219%
No shower too large	36	61	33	92.3077%
Total extra energy O.K.	36	58	32	100%
Ks daughters PID	35	58	21	97.2222%
Lepton PID	3	58	21	8.57143%
Ks flight signif O.K.	2	54	19	66.6667%

D⁺ → K_s μ/e ν

Looking at K_s μ ν / K_s e ν

D_s → φ e ν

Note: Fixed π⁰ η problem (actually two problems)

Regenerated MC using the version 2 DTags and the regenerated monte carlo (no data 48 dskim yet).

K_s stuff

M_KK

D_s → φ e ν

Data φ mass comparison
Cut tightly in KKπ for "prompt" D_s: 25 MeV window on recoil mass (2102 MeV - 2127 MeV), 30 MeV window on D_s mass (1950 MeV - 1980 MeV).
Data vs. Charm φ mass (Cont is small for this mode; forgot to put it back in)
Data vs. Charm φ mass (Charm scaled by 18.0 instead of 20.0)

D_s mass sideband comparison
Reconstruct φ and e, then look at sideband region for D_s mass (low sideband: 1870 MeV - 1900 MeV; high sideband: 2020 MeV - 2050 MeV)

Ds Tag Mode	All MC Counts	φ e ν, good recon	φ e ν bad recon	BG	Expected (MC)	Measured (Data)
Ks K	2	0	1	1	.1	1
K K π	30	2	27	1	1.5	1
Ks K π0	15	0	14	1	.75	0
Ks Ks π	1	0	0	1	.05	1
K K π π0	122	1	121	0	6	3
Ks K+ π π	4	0	2	2	.25	0
Ks K- π π	1	0	1	0	.05	0
π π π	17	2	5	10	.85	0
π η	2	0	2	0	.1	0
π η'	2	0	1	1	.1	0
π η' -> ρ γ	25	2	13	10	1.25	1

Total Expected: 11.0
Total Observed: 7

D_s → φ e ν

Looking at the φ mass
I'd previously found that loosening the φ mass cut from 15 MeV to 30 MeV about the φ PDG mass improved my S²/(S+B), with a majority of the improvement (half the signal gain) occuring from 15 MeV to 20 MeV.

In particular, I get 6.0±0.2% more signal events from 15 MeV to 30 MeV. This seems in contrast to my half-width at half-maximum of ~3-3.5 MeV for my reconstructed φ mass.
Tightening my cuts (e.g. hit fraction to 0.5) brought the 6.0% down to 5.6%.

The half-width of the φ is 2.13 MeV, so I used MyEvent to look at the generated φ mass spectrum in Monte Carlo. About 4.4% of generated events lie in the 15 MeV to 30 MeV region

I thought it would be fruitful to have a clean sample of φs, so I picked D_s → φ π, cut hard on the D_s, and plotted the invariant KK mass. About 5.0% of MC true φ lie in the 15 MeV to 30 MeV region.

Recoil mass (i.e. momentum) cut
Mass cut
M_KK

Plots of tag shape fit to final D_s mass plot

D_s tag side

More complete tagging plots than what I presented last week. I've superimposed the K_s π π⁰ fit background on the MC determined background. BG in the signal region is above the fit by ~150 events, which is roughly how far the signal overshoots. The overshoot is from the charm part of the backgroud (as compared to continuum).

Is this common to K_s modes? K_sK and K_sK_sπ seem to have similar peaks, although their sharper (double gaussian) peaks aren't affected as much. The two K_sKππ modes don't seem to have a background peak near the signal region.

Status: I'm adding K_s info to my ntuples anyway (I currently don't preserve the information after making cuts), so I'll wait until those are done before looking into it more (unless someone has a bright idea).

D_s SL side: φ optimization

I've looked at signal/background counts and S²/(S+B) for a variety of cuts (φ mass, hit fraction, RICH PID on/off, dE/dx σ).
For simplicity, I only count in the signal D_s mass region.

Lowest frequency: M_φ (5 cuts)
2nd lowest frequency: RICH on/off toggle (2 cuts)
2nd highest frequency: Hit fraction (.3, .5, Tim, .1)
Highest frequency: dE/dx (# σ: 2.0, 2.5, 3.0, 4.5, 6.0)

Higher dE/dx better? Do we need PID at all?

Also note: different D_s modes have very different levels of BG (particularly neutrals).

Final M_Ds after electron cuts (f w/ RICH, TQ) and φ cuts (3 σ dE/dx, effectively no HF, z₀ and r₀ cuts at 5 cm/5 mm). Same w/ 6 σ dE/dx.

Neutrino missing mass with "naive" cuts, without the γ and with the γ

D_s tag side

I've gone back and formalized my D_s tag fitting procedure (although not my final D_s cuts). I now use a crystal ball shape on the appropriate modes (π π π and modes with neutrals).

The procedure:

• Fit to the MC truth shape, using a narrow gaussian + wide gaussian/crystal ball shape. The mean for both shapes is set to be the same, with all other parameters left to float (5 or 7 parameters).
• Correct the area for a systematic undercounting of events with these shapes (+1% correction to fits).
• Fit to the reconstructed shape, fixing N_wide/N_narrow and σ_wide/σ_narrow. At present, I also fix σ_narrow, although it looks like I can let it float.

Results from the reconstructed fits (10x sample, D_s⁺):

Mode	Fit estimate	True counts	# σ
KsK	39693.6 +/- 228.711	38670	4.47546
KKπ	119085 +/- 444.066	119291	-0.464916
KsKπ0	17656.8 +/- 263.991	15448	8.36704
KsKsπ	7842.23 +/- 145.61	7412	2.95469
KKππ0	44502.4 +/- 401.243	44324	0.444508
KsK+ππ	13176.8 +/- 220.204	12987	0.861939
KsK-ππ	23184.2 +/- 208.209	23035	0.716536
πππ	34757.6 +/- 419.867	34651	0.253968
πη	18666 +/- 247.57	19324	-2.65796
ππ0η	447.117 +/- 116.557	596	-1.27734
πη',η'→ππη	11673.3 +/- 125.393	11782	-0.866951
ππ0η',η'→ππη	255.409 +/- 29.319	217	1.31003
πη',η'→ργ	28745.8 +/- 393.813	27665	2.74441
Total	359,686 +/- 1,008	355,402	4.25

Note: I should have at least a ~6% statistical error across the full sample due to the numerator (semileptonic counts).
Note 2: My 1% difference in fit/true is roughly the same size as the correction that I make to force the MC fit counts to match the MC true counts.

Future D_s tagging plans:

• Make sure that the - sign D_s fits are reasonable (independent cross-check).
• Make sure the procedure works (fits converge and give reasonable results) on data-sized samples.
• Check a charged and neutral mode in D⁺ MC and data to make sure that my procedure holds up in real events.

Ignore this

D_s tag side

Using new fitting technique on MC only plots.
Red = Gauss + Crystal Ball. Otherwise, double gaussian.
I scale the fit estimate up by 1.00969 due to systematic underestimation for my chosen shapes.

Mode	Fit estimate	True counts	# σ
KsK	38757.1 +/- 195.921	38645	0.571918
KKπ	118881 +/- 343.133	119158	-0.806379
KsKπ0	15434.8 +/- 123.646	15415	0.160346
KsKsπ	7382.04 +/- 85.5056	7406	-0.280169
KKππ0	44377.3 +/- 209.654	44235	0.678834
KsK+ππ	12896.9 +/- 113.02	12975	-0.690772
KsK-ππ	22852.8 +/- 150.444	23020	-1.1114
πππ	34726.7 +/- 185.463	34570	0.845139
πη	19300.4 +/- 138.271	19238	0.451122
ππ0η	546.539 +/- 23.4078	592	-1.94212
πη',η'→ππη	11683.2 +/- 107.575	11767	-0.779306
ππ0η',η'→ππη	238.161 +/- 18.0388	217	1.17311
πη',η'→ργ	27777.7 +/- 165.866	27625	0.920358

Using new fitting technique on charm generic plots (no cont).
Red = Gauss + Crystal Ball. Otherwise, double gaussian.
I still scale the fit estimate up by 1.00969.

Mode	Fit estimate	True counts	# σ
KsK	39198.7 +/- 215.312	38670	2.45534
KKπ	117541 +/- 438.318	119291	-3.99275
KsKπ0	16630.7 +/- 261.26	15448	4.52695
KsKsπ	7723.68 +/- 143.484	7412	2.17222
KKππ0	42878.6 +/- 396.859	44324	-3.64199
KsK+ππ	12743.9 +/- 216.619	12987	-1.12218
KsK-ππ	23191.4 +/- 220.077	23035	0.710449
πππ	35174.2 +/- 276.428	34651	1.8926
πη	18697.3 +/- 157.536	19324	-3.9781
ππ0η	538.955 +/- 62.0912	596	-0.918732
πη',η'→ππη	11631 +/- 116.831	11782	-1.29239
ππ0η',η'→ππη	259.991 +/- 26.1085	217	1.64664
πη',η'→ργ	27494.6 +/- 258.807	27665	-0.658482
Total	353,704 +/- 875.545	355,402	-1.969

D_s tag side I currently fit the D_s mass spectrum after semileptonic cuts (the SL side) using the MC histograms pulled from the D_s tags (i.e. make D_s cuts, then use the MC truth tagged shape).

In the final analysis, I plan to use an analytic shape to fit my D_s tags, then use that same shape to fit my SL side. The hope is that this is more flexible to any differences in the MC/data (e.g. mass resolution) while still getting a systematic error cancelation.

• Step 1: Extend "Peter-like" cuts to all 13 modes.
• Step 2: Fit using a double gaussian + linear.

# sigma: 1.07044
# sigma: -5.65049
# sigma: 1.03628
# sigma: 1.44001
# sigma: -10.5182
# sigma: -0.360476
# sigma: -0.199277
# sigma: -5.62274
# sigma: -3.54609
# sigma: -213.959
# sigma: -1.88557
# sigma: 6.66927

D_s tag side

The current difference between my D_s tags and Peter's is ~.15%.
Comparison plots of my D_s⁺ tags to Peter's D_s tags.

The differences (in KKππ⁰, the worst offender):

• My charge-summed plots and Peter's charge-summed plots were defined differently (~3%)
• I was using the K fit for the track momentum instead of the π fit. This caused a problem with the 100 MeV π fit, which should reject soft D* daughter π (my π were coming out to ~120 MeV instead of ~80 MeV) (~5%)
• Our recoil mass cuts were a little bit different:
  Mine:
  • Veto all events with M_recoil < 2099 MeV (true should be ~2112 MeV).
  • Veto on track momenta, KKπ mass, etc.
  • Choose best candidate for each charge by minimizing |M_recoil - 2112 MeV|
  Peter's:
  • Veto all events with M_recoil < 2051 MeV.
  • Veto on track momenta, KKπ mass, etc.
  • Choose best candidate for each charge by minimizing |M_recoil - 2112 MeV|
  • Veto any best candidate with M_recoil < 2099 MeV.

SL side

I fit to the D_s mass for all events that pass a φ and e cut, using three different methods (10x sample):

• Sum all modes & fit to total with MC shape + linear BG
• Sum all neutral modes (w/ γ) and charged-only modes (e.g. KKπ) & fit each to MC shape + linear BG
• Fit each mode to MC shape + linear BG

• Each fit has 3 parameters. The D_s mass MC shape is taken from true D_s on the tag side (not just semileptonic events).
• Multiple candidates allowed -- only relevant for neutral modes due to extra tracks cut

Results of fit for each mode (10x sample):

Count SL side counts:

• After trying to get a systematic procedure/BG estimate for the cut and count method of getting the φ e ν BR, I migrated toward using a fit on the D_s mass.
• I made a simple minded fit using the crystal ball and putting all modes into one plot, allowing multiple candidates, and choosing a best candidate by lowest U (or by best φ, which still allows multiple candidates for neutrals).

  Results in 10x sample are close for an obviously flawed signal shape -- 3057.3 +/- 86.2 when 3108 true, and 2797.5 +/- 79.9 when 2882 true, for multiple candidates and best φ, respectively.

• My future method (in progress) is to use the true D_s mass shape from MC (taken from the tag side), and fit that + a linear BG for each of my 13 modes.

• I (blindly) looked at a variety of cuts (e.g. pull mass, # σ, etc.) on the π⁰ -- no luck in reproducing Peter's plots
• Peter finally had some time & was able to produce an event list for me!
  • Big issue: His event list and my event list differ in raw counts by about 2% (his higher), but our plots are different at the 15% level (mine higher) -- something's strange... Revisit assumptions:
    • Are the plots Peter gave me the same as the plots in his CBX?
      Yes. Looking at his CBX shows the plots to be identical to the comparable Roofit ones he gave me.
    • Are the plots I'm using for comparison the plots that are from his CBX?
      No. The CBX gives the D_s⁺ and D_s^- plots individually, but I'm using his summed plot to compare against my summed plots.
    • I initially tested the summed plot in the modes K_sK and KKπ. Did I miss something in those modes?
      No. I had these modes pegged correctly.
    • If summing + and - plots works in K_sK and KKπ, it should be good all the time, right?
      No. After all, a D_s⁺ will become a D_s^- just by swapping out a π⁺ and a π^-
  • Aside: it looks like there are some E₉/E₂₅ differences in our showers

Future Plans:

• Make sure Peter & my KKππ⁰ + and - plots compare well.
• Finish SL fits with MC truth D_s mass shape + linear function

Note: BR(D_s → φ e ν) = N_SL+tag / (N_tag * ε_SL)

Outstanding analysis issues:

• D_s Tag
  
  • Peter did 6 D_s modes, I have 13. Make the other 7 modes more "Peter-like" for consistency (and, of course, so that I can more easily adopt his systematics)
    • Recoil mass cut instead of M_bc (both effectively momentum cuts on the D_s
    • See if any of Peter's sytematics need to be redone/adapted for the new modes
    • Remove intermediate particles in the other 7 modes to smooth out the background for the # of tags fit
  • **Understand my peaking background in D_s tags (from true D_s, other modes). This also involves taking a second look at my D_s truth tagging.
  • **Figure out my π⁰ difference relative to Peter
  • Add continuum, radiative return, and τ to my tagging
  • Fit using Peter's functions to match his actual number of tags -- also, count up the statistical and systematic errors
• ε_SL
  
  • Check (correlated w/ SL) systematics when have final cuts
• D_s SL side
  
  • **Get an estimate for the level of background (passing non-φ e ν)
  • Get a systematics procedure
  • Optimize cuts (φ/K, best candidate D_s)
  • Add in η e ν

Requested loose φ/γ comparison
I've implemented some very simple γ cuts (my looser shower quality + an energy cut from 105 MeV to 177 MeV) and looked at what effect this would have on my analysis. Note that my efficiency for getting the correct photon is closer to 70% than to the table's 87%. No MM* cut is made (perhaps this was the point?).
Note: This is 20x the half sample (Koloina would have ~1,000 events in this sample)

Cuts	Passing φ e ν events	Charm, not φ e ν	Relative fraction of events
Loose φ, no γ (my standard)	2,815	84 [2.9%]	100% (defined)
Loose φ, has γ (my standard)	2,445	57 [2.3%]	87%
Normal φ, no γ (my standard)	1,901	39 [2.0%]	68%
Normal φ, has γ (my standard)	1,652	26 [1.5%]	59%

Determining amount of background

There are generally two sources of background that pass all cuts:

• D_s semileptonic to some other mode (often η e ν). This is ~1/3 of the estimated MC background
• D(_s)(*)D(_s)(*) to semileptonic (e.g. K e ν) or even leptonic modes (e.g. τ ν) with random combinations for the D_s and sometimes the φ

The extent to which I care:
      I expect ~300 events in the full sample (~150 in the half sample), which gives a statistical error of ~6%. With my existing φ and extra track cuts, my background accounts for about ~3% of the observed events.

Bottom line:
      I don't really have a feel for how much I can trust my Monte Carlo on the random BG combinations (depends on the non-SL/L side of D decays), but I only need to be confident to within a factor of ~2.

Note:
      BG shouldn't (and doesn't appear to) peak in D_s mass. Right now, I'm making the φ cuts, e cuts, and most of the D_s cuts, then looking at the D_s mass (which I normally cut on at 3 σ). My goal is to make the non-SL background stand out from the SL bad-D_s combinations.

Possible explanation: e cuts should be the same, but I should have a higher efficiency with D_s, φ, and the D_s* γ.

Investigation into φ+e:
I have looser cuts on the φ in three main areas:

• My φ mass cut is 30 MeV (overkill) instead of 10 MeV
• My track quality cuts are looser for the φ's daughter kaon only (10 cm/mm instead of 5 cm/mm)
• My minimum hit fraction cut is .1 (no real HF cut) instead of .5

Hit fraction cut:
Here's the efficiency of the hit fraction cut, by φ momentum.
This does not include BR(φ → KK), so the maximum possible efficiency is 49.1%

pφ	Basic cuts, HF > 0.5	Basic cuts, Tim's HF	Basic cuts, no HF cut
0 GeV - 0.2 GeV (1,000)	5.9% (77.6%)	6.9% (90.8%)	7.6%
0.2 GeV - 0.4 GeV (6,514)	15.3% (83.4%)	17.2% (93.7%)	18.4%
0.4 GeV - 0.6 GeV (12,109)	29.4% (90.1%)	31.6% (96.8%)	32.6%
0.6 GeV - 0.8 GeV (9,732)	36.4% (93.7%)	38.2% (98.3%)	38.9%
0.8 GeV - 1.0 GeV (2,889)	39.4% (95.5%)	40.8% (98.9%)	41.3%
1.0 GeV+ (51)	31.4% (88.9%)	35.3% (100.0%)	35.3%
All p integrated (32,295)	28.9% (91.5%)	30.8% (97.5%)	31.6%

Track quality cut:
Here is the impact of the looser TQ cuts (10 cm/mm) when I don't have any hit fraction applied (there is a correlation between the HF cut and the TQ cut -- looser TQ only buys you ~2% after you make an HF cut)

pφ	10 cm/mm TQ & 10 MeV mass	5 cm/mm TQ & 10 MeV mass
0 GeV - 0.2 GeV (1,000)	9.7%	7.6% (78.3%)
0.2 GeV - 0.4 GeV (6,514)	20.3%	18.4% (90.6%)
0.4 GeV - 0.6 GeV (12,109)	35.8%	32.6% (91.1%)
0.6 GeV - 0.8 GeV (9,732)	41.6%	38.9% (93.4%)
0.8 GeV - 1.0 GeV (2,889)	43.5%	41.3% (94.9%)
1.0 GeV+ (51)	37.3%	35.3% (94.6%)
All p integrated (32,295)	34.3%	31.6% (92.3%)

φ mass cut
Here's the impact of an overly wide (30 MeV) φ mass cut to the normal φ mass cut (10 MeV).
I'm using the loose TQ and no hit fraction.

pφ	30 MeV mass	10 MeV mass
0 GeV - 0.2 GeV (1,000)	10.6%	9.7% (91.5%)
0.2 GeV - 0.4 GeV (6,514)	21.9%	20.3% (92.7%)
0.4 GeV - 0.6 GeV (12,109)	38.1%	35.8% (94.0%)
0.6 GeV - 0.8 GeV (9,732)	44.3%	41.6% (93.9%)
0.8 GeV - 1.0 GeV (2,889)	46.0%	43.5% (94.6%)
1.0 GeV+ (51)	43.1%	37.3% (86.5%)
All p integrated (32,295)	36.5%	34.3% (94.0%)

Overall impact of all the cuts on ε_SL
Rather than the φ efficiency, I use the semileptonic efficiency for this comparison (including the e, which is soft for high p_φ).
Errors are about 0.5% on my values and 0.3% on Koloina's quoted values (except the first and last rows).

εSL	Justin	Justin-faking-Koloina's cuts	Koloina quoted (independent sample)
0 GeV - 0.2 GeV	9.2% (100.0%)	5.2% (56.5%)	2.5% (27.7%)
0.2 GeV - 0.4 GeV	17.0% (100.0%)	11.8% (69.6%)	7.9% (46.8%)
0.4 GeV - 0.6 GeV	27.6% (100.0%)	21.2% (76.9%)	18.8% (68.1%)
0.6 GeV - 0.8 GeV	29.7% (100.0%)	24.5% (82.7%)	25.7% (86.7%)
0.8 GeV - 1.0 GeV	27.8% (100.0%)	23.6% (85.0%)	25.7% (92.5%)
1.0 GeV+	19.6% (100.0%)	13.7% (70.0%)	25.7% (131.3%)
All p integrated	25.5% (100.0%)	20.0% (78.5%)	17.7% (69.4%)

Summary of efficiency differences, Justin/Koloina

• Difference in finding the D_s*'s daughter γ: 59%
• Differnece in φ cuts: 69%
• Difference in D_s modes: 89%*

Comparison with Jon: I haven't done much recently. I'm putting this aside for now. We have a meeting Tuesday; perhaps this will be discussed.

Over all data (d39-d41 and d47,d48), I expect 296 φeν using Peter's D_s and 315 φeν using my D_s. About 5% of observed events are expected to be background from existing MC.

Cuts	(NS)1/2	NB
Peter	17.2	13
Justin	17.8	15

Investigating φ e ν BG
      D_s mass with good e, φ
      D_s mass with good e, φ, and D_s

A long story in one plot: My D_s faking Peter (blue lines) vs. Peter's D_s (dots). The best candidate is chosen (using recoil mass) for each D_s charge.

Cuts involved: DTagging cuts

Note: Peter only has one π⁰ mode, and this mode also has the highest number of multiple candidates (although KKπ and 3π also have several multiple candidates).

Current Status: I tried several different cut combinations, to no avail. Peter has been very helpful so far, but he hasn't responded since Saturday (prepping for CLEO meeting?). I'll bug him again next week.

In vs. Out redux -- η e ν

Sample	Passing SL+tag	Expected BR	Num σ
Data-size 1	261	2.66%	+0.81
Data-size 2	247	2.52%	-0.06
Data-size 3	231	2.36%	-1.06
Data-size 4	235	2.40%	-0.81
Data-size 5	276	2.82%	+1.81
Data-size 6	232	2.37%	-1.00
Data-size 7	249	2.54%	+0.06
Data-size 8	273	2.79%	+1.62
Data-size 9	254	2.59%	+0.38
Data-size 10	244	2.49%	-0.25
Blind d39	872	2.41%	-1.48
Blind d40	2,101	2.58%	+0.89
Blind d41	2,006	2.56%	+0.18
Total	4,979	2.54%	N/A

Overall reduced Χ² for the 20 samples: 1.13

These BRs are using:

• N_DsDs* = 5,643,806 (assume 1/20th per sample)
• N^{gen, MC}_{η e ν + tag} = 285,198
• N^{obs, MC}_{η e ν + tag} = 4,951
• 92% of passing events are signal φ e ν

Currently trying to replicate Peter Onyisi's D_s plots from CBX07-14.
I see invariant mass peaks, but no quantitative comparison yet :(

Comparison with Jon

η e ν

Current Work: Since my replication of Jon's analysis isn't terribly far along, I've just looked at the absolute issue: Why are 25% of my η e ν events BG?

BG events: There are many different types of BG events that pass my cuts. Several of these have π⁰ showers faking η showers, so I first made a splitoff and π⁰ rejection cut.
About 1/3 of the remainder are D_s → η' e ν, where the η' → π⁰ π⁰ η (no explicit rejection on extra π⁰s). Overall, ~55% of the remainder are D_s D_s* at all. The rest are primarily D⁰ semileptonic modes, where a D_s tag happens to form.

η Cut	η e ν events	Non-η e ν events	S2 / (S+B) (x103
Pullmass < 3.0	5,136	1,682	3.9
(PM < 3.0) + splitoff	4,885	1,485	3.7
(PM < 3.0) + SO + π0 rejection	4,246	687	3.7
(PM < 3.0) + SO + π0 + (MM2 < 0.5 GeV)2	4,032	211	3.8

MM² plot

In vs. Out redux -- φ e ν

Sample	Passing SL+tag	Expected BR
Data-size 1	182	2.22%
Data-size 2	168	2.04%
Data-size 3	140	1.70%
Data-size 4	168	2.04%
Data-size 5	176	2.14%
Data-size 6	161	1.96%
Data-size 7	162	1.97%
Data-size 8	169	2.06%
Blind d39	612	2.016%
Blind d40	1,356	1.986%
Blind d41	1,358	2.067%
Total	3,326	2.024%

These BRs are using:

• N_DsDs* = 5,643,806 (assume 1/20th per sample)
• N^{gen, MC}_{φ e ν + tag} = 227,124
• N^{obs, MC}_{φ e ν + tag} = 3,306
• 95.3% of passing events are signal φ e ν

Cross-check, Jon

Ds Tag Mode	Justin-faking Jon, recon	Jon recon	Justin-faking Jon, MC true	Jon fit tags
Ks K	103,100	100,603	26,705	29,138
K K π	572,000	595,918	85,015	93,229
Ks K π0	205,200	164,000	10,211	11,805
Ks Ks π	57,440	38,230	5,360	5,046
K K π π0	1,114,000	1,190,244	33,662	38,342
Ks K+ π π	299,300	224,505	10,478	10,229
Ks K- π π	193,000	156,093	17,688	17,988
π π π	263,200	281,210	30,999	33,307
π η	46,780	46,331	11,231	13,463
π π0 η	497,100	444,666	37,441	51,041
π η'	32,510	31,772	7,258	9,532
π π0 η'	117,400	111,743	8,155	12,181
π η' -> ρ γ	222,900	197,975	19,969	23,073

MC consistency check

SL Mode	D39 BR	D40 BR	DECAY.DEC
φ e ν	2.03% [± 0.01%]	2.00% [± 0.01%]	2.02%
η e ν	2.52% [± 0.01%]	2.53% [± 0.01%]	2.53%

Note: There were 1.04 M D_sD_s* in D39 and 2.34 M in D40. There were about 42 K φ e ν in D39 and 94 K in D40.

In vs. Out Test

This yields a branching ratio for φ e ν of (2.02 ± 0.16)% based on 164 * 0.96 = 157 blind, reconstructed events. DECAY.DEC value is 2.020%.
I also get a branching ratio for η e ν of (2.96 ± 0.17)% based on 386 * 0.744 = 287 blind, reconstructed events. DECAY.DEC value is 2.530%.
Note: For η e ν, the ratio of reconstructed events in each sample doesn't match ratio of sample sizes by ~14% -- this accounts for essentially all of the surplus.

Cross-check, Jon

Ds Tag Mode	Justin MC true tags	Jon fit tags
Ks K	56,861	58,276
K K π	170,540	186,458
Ks K π0	22,863	23,610
Ks Ks π	14,004	10,092
K K π π0	67,455	76,684
Ks K+ π π	24,787	20,458
Ks K- π π	42,966	35,976
π π π	62,035	66,614
π η	22,491	26,926
π π0 η	74,920	102,082
π η'	14,473	19,064
π π0 η'	16,336	24,362
π η' -> ρ γ	40,588	46,146
Total	630,319	696,748

Full generic sample, tag+γ+SL
Using my approximation of Jon's cuts (D39 + D40 only):

SL Mode	Justin true	Jon true	Justin BG	Jon BG
φ e ν	963	1,306	34	62
η e ν	1,747	2,190	1,292	72

Aside: Cross-check with Koloina's shows similar issue. There is some electron oddness (high fakes) in both. Looking into it...

Comparison with results of other groups

Group Status Summary:

Group/cuts	Scaled MC events	Data events
Syracuse	45.6	43.5 ± 6.7
Rochester	65.3	67
Mine, no γ	162	--
Mine, 70%-80% εγ	113-130	--
Mine, 70%-80% εγ, tight K and 10 MeV φ	89-102	--

Cross-check: η e ν

φ/η consistency

Event cuts	Ratio
φ e ν: (My loose K/φ w/70% γ)/(Jon's)	1.73
φ e ν: (My best guess K/φ w/70% γ)/(Jon's)	1.53
η e ν: (My η w/70% γ)/(Jon's)	1.55

In vs. Out

Blind/MC consistency check:

• In blind data-sized MC sample made from dataset 40, 164 events pass all cuts.
• From dataset 39 MC (a 3.6x current data sample), estimate that 96% of passing events are signal.
• In dataset 39 MC, have 586 signal events passing.
• This means that we should have
  BR^meas./BR^decay.dec = 164 * 0.96 * 3.6 / 586 = 0.971 ± 0.076

Event quality cut

• Extra tracks
• Correct charges in event (D_s vs. electron)
• No multi-use of tracks (rejection of a track used in both the D_s and a φ's daughter kaon)

Previously:

Cuts	φ e ν	DsDs*	Charm	Cont	Charm - DsDs*	DsDs* - φ e ν
Pass e cuts	3,247	14,232	45,830	2,359	31,598	10,985
Pass φ cuts	1,267	3,279	4,972	88	1,693	2,012
Pass event quality cuts (no multi-use of tracks, charges match, no extra tracks)	588	604	618	0	14	16

Now:

Cuts	φ e ν	DsDs*	Charm	Cont	Charm - DsDs*	DsDs* - φ e ν
Pass e cuts	3,247	14,232	45,830	2,359	31,598	10,985
Pass φ cuts	1,267	3,279	4,972	88	1,693	2,012
No extra tracks	872	1,926	2,253	12	327	1,054
Proper charges	852	1,885	2,136	7	251	1,033
No multi-use (Ds)	588	604	618	0	14	16
No e/K multi-use	586	600	612	0	12	14

These multi-use events come almost entirely from KKπ (mode 1) and KKππ⁰ (mode 4).
The tracks are lowish momentum kaons (~200-400 MeV) that are not usually from the semileptonic φ (they are from the D_s ~2/3 of the time, with about 2/3 of the remainder being incorrect in both the D_s and the φ).

This should mean that a tighter φ cut will make some of these events get cut at the φ cut stage instead of the multi-use cut.

With 10 MeV γ cut:

Cuts	φ e ν	DsDs*	Charm	Charm - DsDs*	DsDs* - φ e ν
Pass e cuts	3,247	14,232	45,830	31,598	10,985
Pass φ cuts	1,085	2,714	3,510	796	1,629
No extra tracks	719	1,578	1,736	158	859
Proper charges	703	1,549	1,678	129	846
No multi-use (Ds)	486	492	498	6	6
No e/K multi-use	485	491	496	5	6

Looked into background and the cause for QQId-wrong particles in semileptonic events

Background Investigation:

Cuts	φ e ν	DsDs*	Charm	Cont	Charm - DsDs*	DsDs* - φ e ν
All events			7,142,659*	2,068,865*
Has Ds w/ 1920 < mDs < 2015 1980 < Mbc < 2100	6,178	248,348	1,023,371	262,459	775,023	242,170
Pass 3σ mDs	5,001	219,574	681,262	173,038	461,688	214,573
Pass 2005 < Mbc < 2075	4,547	206,938	518,788	117,746	311,850	202,391
Pass e cuts	3,247	14,232	45,830	2,359	31,598	10,985
Pass φ cuts	1,267	3,279	4,972	88	1,693	2,012
Pass event quality cuts (no multi-use of tracks, charges match, no extra tracks)	588	604	618	0	14	16

* from generated information, charm should be 9.25M and continuum should be 4.02M

Looking into QQIded-wrong γ in semileptonic events

QQId wrong particle	Events	%
All events	4,909	100%
Electron	0	0%
Ds	262	5.3%
φ	362	7.4% (4.6% w/ tight TQ)
γ	4,832	98.4%
γ (splitoff O.K.)	1,824	37%

Checked particle and parent QQId info for γ

Checked γ multiplicity in reconstructed events

Reconstruct without γ

U plot for ν+γ (since no γ reconstruction)

Type	# combinations	# events
All reconstructed	1591	1535
SL, correct QQIds	1450	1436*
SL, mis-QQIds	99	51
Non-SL	42	45

* 1386 unique; 38 with at least one mis-QQId; 12 with multiple correct QQId combinations (these go away with hf > 0.5 cut on kaons)

To add:

• Reasons for misQQIds
• Event mult. over all 13 modes

BR(D_s → heν) = (# tag + SL) / (#tag * ε_SL)

Currently looking at the (#tag + SL) part.

The Problem?: Often get extra photons in valid events: Missing mass plot (or U=E_miss - p_miss plot)

Intermediate Solution: Plot E_γ and fit.

Final Solution?:

1. Estimate the number of events where we only get a false photon in a valid event (don't trust the MC unless forced to). In MC, 6.9% of signal events pass with all particles tagged correctly (blue); 2.9% pass when missing at least one particle (red not blue).
2. Use these events for additional statistics.

Analysis summary

Ultimate Goal: Measure BR(D_s → heν) where h ⊂ (φ, η, η').

Primary Challenge: ν is unobservable.

Other Challenge: D_s mesons occur predominantly in D_s D_s*.

General Procedure:

• Target D_s D_s* events, where D_s* → D_s γ
• Isolate events by reconstructing all particles except the ν and show its existence via missing mass or equivalent (U = E_miss - p_miss)¹
• Get a BR by counting tags (defined as everything except the semileptonic D_s: here a D_s + γ) and seeing how often candidate events occur when such a tag exists:
  BR(D_s → heν) = (# tag + SL) / (#tag * ε_SL)
• Overall, need to:
  • Count # D_s + γ tags
  • Measure ε_SL (using MC only)
  • Count # tag + SL events

Counting D_s + γ tags:

• Choose several D_s modes to reconstruct for the tagging side:
  • Want a large ε * BR
  • Background is non-trivial for most modes, so most statistical power comes from a handful of available D_s modes
  • Originally used 8 D_s modes to intermediate particles (e.g. φ π, K* K, η ρ).
  • Now use 13 D_s modes to (mostly) final particles (e.g. KK π, η π π⁰)
    • Original modes were generally cleaner, but not hugely so. The same statistical power is probably kept for the primary modes (e.g. KKπ) because the background is so low. Additionally, some modes like φ π vs. f₀ π were not really distinguishable anyway. Other modes, like the ρ modes had such weak intermediate particle cuts that background wasn't substantially reduced, and it was simpler to allow non-resonant π π⁰ to be treated as tags along with the ρ

  ---

  
  (2/14/08)

  D_s semileptonic tags

  Changed D_s mass bin size from 10 MeV to 5 MeV.
  20x sample fit/expected peaking BG (1st iteration): 1.0195
  20x sample fit/expected signal (1st iteration): 1.01395
  20x sample fit/expected peaking BG (2nd iteration): 0.986421
  

  Tags vs. D_s mass with 5 MeV bins

  ---

  
  (2/7/08)

  D_s semileptonic tags

  Results of iterated fits (use first fit signal estimate to get better peaking BG estimate):

  File #	MC tagged signal (center)	Estimated, MC shape(center)	Estimated, MC shape iterated (center)	MC tagged signal (all)	Estimated, MC shape (all)	Estimated, MC shape iterated (all)
  1	890	941.189 +/- 97.4627	962.483 +/- 97.5407	916	956.047 +/- 130.686	997.928 +/- 130.801
  2	959	911.32 +/- 99.0369	933.594 +/- 99.1153	979	915.49 +/- 132.519	959.335 +/- 132.635
  3	871	1148.93 +/- 97.8826	1173.61 +/- 97.9706	902	1220.35 +/- 129.043	1268.68 +/- 129.175
  4	921	973.769 +/- 98.9356	996.283 +/- 99.0167	944	984.966 +/- 131.205	1029.05 +/- 131.326
  5	937	944.583 +/- 101.582	965.483 +/- 101.654	969	865.309 +/- 135.542	906.636 +/- 135.652
  6	968	1087.49 +/- 100.7	1111.49 +/- 100.785	991	1085.33 +/- 132.732	1132.4 +/- 132.859
  7	927	947.992 +/- 100.285	968.476 +/- 100.359	954	981.336 +/- 132.182	1021.58 +/- 132.292
  8	969	966.406 +/- 100.044	986.64 +/- 100.117	1006	890.905 +/- 132.48	930.657 +/- 132.589
  9	871	696.619 +/- 95.9886	712.196 +/- 96.0467	897	708.634 +/- 128.465	739.329 +/- 128.551
  10	949	928.467 +/- 99.7403	950.562 +/- 99.8177	980	889.885 +/- 132.685	933.348 +/- 132.802
  11	922	974.944 +/- 99.0731	995.334 +/- 99.1465	944	931.347 +/- 131.751	971.286 +/- 131.861
  12	936	784.568 +/- 99.1069	802.024 +/- 99.1702	960	744.516 +/- 132.795	778.913 +/- 132.888
  13	918	880.631 +/- 97.9478	898.745 +/- 98.0114	945	926.175 +/- 130.777	962.027 +/- 130.872
  14	907	880.27 +/- 99.7006	900.963 +/- 99.7754	930	878.651 +/- 132.318	919.465 +/- 132.43
  15	940	1086.18 +/- 101.801	1109.88 +/- 101.885	959	1114.3 +/- 132.905	1160.75 +/- 133.031
  16	914	973.522 +/- 101.78	997.386 +/- 101.864	937	946.152 +/- 134.859	992.823 +/- 134.982
  17	919	979.718 +/- 100.436	998.934 +/- 100.503	950	955.906 +/- 132.715	993.672 +/- 132.816
  18	951	975.983 +/- 99.8187	998.542 +/- 99.8975	988	1001 +/- 132.437	1045.33 +/- 132.554
  19	941	930.06 +/- 99.1743	949.599 +/- 99.2428	959	942.326 +/- 131.76	980.886 +/- 131.864
  20	910	833.367 +/- 96.8454	853.105 +/- 96.916	944	824.036 +/- 130.125	862.897 +/- 130.23
  Χ2/20	N/A	0.998	1.142	N/A	0.803	0.877
  20x sample	18520	18764.7 +/- 444.372	19184.1 +/- 444.706	19054	18585.3 +/- 590.263	19409.6 +/- 590.761

  Over 20x sample, first estimate for peaking BG is 1.88% high; second estimate after repeating fit is 1.44% low.

  ---

  
  (1/31/08)

  D_s semileptonic tags

  Signal and peaking BG by D_s mass.

  Fit to 20x sample

  .

  Data size sample #	MC tagged signal (center)	Signal using MC shape (center)	MC tagged signal (all)	Signal using MC shape (all)
  5	937	955.399 +/- 101.619	969	886.696 +/- 135.599
  6	968	1167.98 +/- 100.985	991	1243.25 +/- 133.157
  7	927	1013.62 +/- 100.522	954	1110.21 +/- 132.534
  8	969	1052.89 +/- 100.356	1006	1060.8 +/- 132.945
  9	871	749.394 +/- 96.1856	897	812.62 +/- 128.756
  18520	18760.3 +/- 444.368	19054	18576.5 +/- 590.258

  Working on:

  • Making bin widths parameters
  • (?) Iterate fit one more time (feed signal counts back in & find peaking BG again)
  • Extend to other modes (this is just π π⁰ η')
  • Double-check past work
  • Write summary of past work & results (CBX)

  Systematic ideas:

  • Use (data R/L)/(MC R/L) ratio as estimate for systematic
  • Use data R only to get weight, then use data L only

  ---

  
  (1/30/08)

  D_s semileptonic tags

  File sum plots

  ---

  
  (1/24/08)

  D_s semileptonic tags

  Current Goal(s):

  • Finalize procedure to remove peaking background from bad D_s with good γ
  • Get systematic from the peaking BG procedure and any other tagging systematics
  • Apply peaking BG subtraction procedure to all modes (currently testing in π π⁰, η' w/ η' → π π η since here peaking BG is roughly equal in magnitude to signal);

  Distribution of peaking BG/signal in 20x MC sample (ignore black line).

  Procedures:

  • Fit E_γ for every 10 MeV D_s mass slice
  • Estimate peaking BG by using low D_s mass sideband only.
  • Estimate peaking BG by using high D_s mass sideband only.
  • Estimate peaking BG by using an average of the low & high D_s mass sidebands.
  • Estimate peaking BG by assuming the MC has the correct relative amounts in each D_s mass bin and getting the overall weight from the sidebands.
  • Use zero peaking BG, fitting only the signal shape.

  Data size sample #	MC tagged signal	Signal using low sideband	Signal using high sideband	Signal using average sideband	Signal using MC shape	Signal assuming no peaking BG
  5	937	1070.75 ± 102.019	1247.57 ± 102.628	1141.35 ± 102.262	1064.29 ± 101.994	1868.06 ± 0
  6	968	1199.12 ± 101.096	1105.76 ± 100.765	1161.75 ± 100.964	1222.02 ± 101.177	1618.17 ± 0
  7	927	1002.82 ± 100.486	1131.56 ± 100.952	1054.25 ± 100.672	1077.72 ± 100.755	1548.43 ± 0
  8	969	969.068 ± 100.049	1231.97 ± 100.999	1073.96 ± 100.427	1115.7 ± 100.582	1576.87 ± 0
  9	871	656.695 ± 95.8351	981.392 ± 97.0517	786.126 ± 96.3191	807.095 ± 96.4012	1230.57 ± 0

  ---

  
  (1/17/08)

  D_s semileptonic tags

  Quick overview:

  • Goal: Find branching ratio (form factors?) for D_s → φ/η(/η'?) e ν
  • Procedure: Look in D_s D_s* events, where D_s* → D_s γ, one D_s goes to a tagged mode, and the other D_s has an electron and a φ/η (with zero missing mass or equivalent).
  • Tagged Modes:
    • 5 "Clean" Modes: K_s K, K K π, π π π, π η, π &eta' w/ η' → π π η
    • 3 "Medium" Modes:: K_s K_s π, K_s K⁺ π π, K_s K^- π π
    • 5 "Dirty" Modes:: K_s K π⁰, K K π π⁰, π π⁰ η, π π⁰, η' w/ η' → π π η, η' π w/ η' → &rho &gamma
  • Tags: Use D_s + γ as the tag, fitting charm+cont+signal histogram to a plot of E_γ (have also done recoil mass).
  • Semileptonic (full event): Find presence of electron and φ/η, cut on missing mass (or U), and fit to a plot of E_γ.
  Current semileptonic (full event) issues:
  • Perhaps drop missing mass/U cut altogether (i.e. there's effectively no background that fakes a tag + electron + φ/η)? Looks like efficiency in MC goes slightly up without added background, at least for φ studies.
  • "Background" is mostly non-D_s* daughter showers in real events (variety of causes). Some fraction of these events don't have a real shower found, so they might be used to improve statistics.
  Current tagging issues:
  • Problem: When looking at systematic errors from the histogram fit by considering other background shapes, I found that some of the non-clean modes had peaking background from bad D_s + real γ (typically from stealing a π or π⁰ from the other side D_s).
  • Solution: Assume that the MC has a reasonable shape for the peaking background, find the amount of peaking background from the D_s mass sidebands, then include this as a fixed amount in the fit.
  • Problem: Naive error calculations on the bad D_s sideband fits didn't give the expected errors. In a typical data-sized sample:

    Background	σN/N	Expected Error (1/√N or √(S+B)/S)
    Charm	6.8%	~1%
    Continuum	13.2%	~1%
    Peaking BG	13.2%	11.0%

  • Solution:
    • Note that the # of entries doesn't include underflow/overflow! (Corrected in above table)
    • Watch the correlations between each fit -- Charm & continuum have a correlation coefficient of -.97!
    • If I fix the continuum part of the fit, the errors come out as naively expected (1.5% for charm, 10% for signal).
    • Double-check by making 3 bin histogram, explicitly fitting the outer bins with charm only, fixing the charm weight, and fitting the middle with peaking background (σ_N/N vs. expected: 0.88% vs. 0.89% for outer bins, 10.35% vs. 10.33% for middle).
  Present Work:
  • Use flat assumption for peaking BG with D_s mass or something more sophisticated. Have sideband/center scaling of 1.17 assuming flat, 0.895 from counting.

  ---

  
  (11/15/07)

  D_s semileptonic tags

  Linear fit example

  ---

  
  (11/1/07)

  D_s semileptonic tags

  MC data-size sample fits
  New data fit (now 823 signal + 712 peaking BG).

  MC ratio of peaking BG to Signal is ~95% (double-check). Data ratio of peaking BG to signal is ~(86.5+/-3)%.

  Current mysteries:

  • Why are my errors still so high (in MC and in data)? Expect ~6% in signal and ~1% in charm BG; have ~12% in signal, ~6% in charm BG.
  • Different distribution of peaking BG by D_s mass in MC vs. data?

  ---

  
  (10/25/07)

  D_s semileptonic tags

  	Signal			Peaking BG
  Procedure	Truth	Fit Result	Ratio	Truth	Fit Result	Ratio
  (Original) Peaking part in charm BG shape	1091	1270	+16%	N/A	N/A	N/A
  Peaking BG determined from sideband (sample 1)	1122	1300	+16%	1203	1265	+5%
  Peaking BG determined from sideband (sample 2)	992	1090	-9%	1297	1122	-13%

  In data (previously 0 within errors; now 816 signal + 692 peaking BG).

  ---

  
  (10/11/07)

  D_s semileptonic tags

  E_γ for sideband region (fit with signal shape and Bad D_s shape).

  Signal shape vs. Bad D_s shape

  ---

  
  (10/4/07)

  D_s semileptonic tags

  A brief history of the D_s+γ tagging problem:
  

  • I needed an estimate for the systematic on using histograms as BG function for recoil mass vs. E_γ, so compared to polynomail function
  • The 5 "Clean" modes (K_sK, KKπ, πππ, πη, and πη') didn't have much of a difference in the # of signal events estimated using a polynomial vs. histogram BGs (except maybe πππ).
  • Several of the 8 "Unclean" modes had a large difference in the # of signal events found from the histogram BGs vs. the polynomial BGs. When there was a significant difference, the histogram method was the accurate one.
  • I identified the problem to be real E_γ pairing with bad D_s. The bad D_s tended to steal a π or π⁰ from the other side D_s.
  • My method so far has been to take 10 MeV slices of the D_s mass, fit the resultant E_γ spectrum with a histogram BG, and plot as a function of mass to determine the "true" signal.

  Systematic estimated by mode (# polynomial/# histogram - 100%)
  Ds Mode	Eγ	Recoil mass
  Ks K	2.73%	-1.87%
  K K π	-0.38%	-2.52%
  π π π	14.6%	-0.27%
  π η	1.1%	2.17%
  π η' (π π η)	0.36%	9.45%
  Ks K π0	82.0%	7.4%
  Ks Ks π	-17.4%	10.2%
  K K π π0	90.1%	-7.7%
  Ks K+ π π	16.3%	27.6%
  Ks K- π π	13.8%	3.7%
  π π0 η	-41.2%	-47.9%
  π π0 η' (π π η)	-5.8%	88.5%
  π η' (ρ γ)	-0.12%	30.2%

  
  For comparison, the worst statistical error in E_γ is K_s K_s π with 13%. "Clean" modes have statistical errors of ~3-6% in E_γ, or ~4-7% in recoil mass (with recoil mass being suspiciously high for several modes -- ~1.4σ after weighted average).

  Slice method results.

  ---

  
  (9/27/07)

  D_s semileptonic tags

  Slice D_s mass and compare bad D_s to signal events.

  ---

  
  (9/20/07)

  D_s semileptonic tags

  D_s mass and E_γ comparisons

  ---

  
  (9/13/07)

  D_s semileptonic tags

  Investigating good γ, bad D_s events:
  
  Correct mistake with good D_s, bad γ events
  D_s mass and M_bc

  ---

  
  (8/30/07)

  D_s semileptonic tags

  Tagging systematic studies:
  Fit with histogram and 6-degree polynomial, finding difference in number of events found:
  

  Mode	γ energy	Recoil mass
  Ks K	2.73%	1.87%
  K K π	0.38%	2.52%
  π π π	14.6%	0.27%
  π η	5.6%	6.26%
  π η' (π π η)	5.44%	8.53%

  Peaking BG discovery
  Peaking BG information

  ---

  
  (8/16/07)

  D_s semileptonic tags

  Results of different tagging procedures:
  D_s + γ tags

  Plots for different tagging procedures:
  Recoil Mass and polynomial background plots

  ---

  
  (7/24/07)

  D_s semileptonic tags

  Event Comparison

  ---

  
  (7/19/07)

  D_s semileptonic tags

  Focus on finalizing tagging:

  • Changed D_s mass cut from 1940 MeV - 1995 MeV to a 3 σ mass cut
  • Reviewed Recoil Mass as potential double-check for the # of tags -- still need to do fit
  • Tried making an M_bc or M_bc* cut to reduce background on tagging.

  Best Candidate U plot

  ---

  
  (7/12/07)

  D_s semileptonic tags

  • Tried different backgrounds for tags -- best were linear and N_charm*charm + N_cont*cont (best = low uncertainty and accurate)
  • Comparison of the tags from all 3 groups.
  • Tried different backgrounds for E_γ fit -- background histogram was still the best, although linear BG is good safety check.

  In vs. Out test:
  

  SL Mode	Decay.dec	MC true	Fit
  φ e ν	2.02%	2.06% (0.10%)	(2.07 ± 0.10)%
  η e ν	2.53%	2.50% (0.10%)	(2.64 ± 0.18)%

  In data:
  

  SL Mode	Justin	John (Roch.)	Koloina (Syr.)
  φ e ν	(2.42 ± 0.35)%	(2.263 ± 0.287)%	(2.51 ± 0.30)%
  η e ν	(2.26 ± 0.51)%	(2.045 ± 0.242)%	(2.440 ± 0.367)%
  η' e ν	???	(0.603 ± 0.248)%	(0.566 ± 0.283)%

  ---

  
  (7/5/07)

  D_s semileptonic tags

  Found two significant problems from last week:

  • FSR semileptonic events were being treated as non-semileptonic events (background).
  • There was a "stray" U cut of ± 50 MeV on my MC truth info, even for the no-U cut procedure.

  FSR Impact:
  

  • BR(φ e ν + X) / BR(φ e ν) = 1.15
  • BR(η e ν + X) / BR(η e ν) = 1.18
  DECAY.DEC branching ratios now reproduced with MC information:
  
  • BR(φ e &nu) = (2.014 ± 0.007)% [Input: 2.02%]
  • BR(η e &nu) = (2.531 ± 0.007)% [Input: 2.53%]

  U cut Impact:
  Efficiency difference:
  ε_{φ e ν, no U cut} / ε_{φ e ν, 50 MeV U cut} = 1.18
  ε_{η e ν, no U cut} / ε_{η e ν, 50 MeV U cut} = 1.34
  ε_{η' e ν, no U cut} / ε_{η' e ν, 50 MeV U cut} = 1.24
  I was using the no U efficiency on the 50 MeV U cut MC sample

  Overall impact:

  • FSR fix closes about 60% of the gap in my MC generated BR vs. MC reconstructed BR (prelim. check)
  • FSR problem should have a data impact since there was peaking background in my fit function.
  • U cut fix won't change the generated/reconstructed gap since the efficiency changes for both. Using no U cut makes the gap worse, since generated goes up while reconstructed value stays roughly the same (checking this.
  • U cut fix will change data value, since effective efficiency on data plots should have been lower. I'm now leaning toward no U cut in the final analysis, however.

  Current work/near-term plans:

  • Changing tag fitting from histogram background to function background
  • Reviewing effects of FSR/U cut fixes.
  • Writing up "note"

  ---

  
  (6/28/07)

  D_s semileptonic tags

  MC mock run through:
  

  • Reweighted charm/continuum to account for 5x vs. 20x samples (made low energy "hump" in E_γ background less prominent)
  • Used 1/3 of the MC to make "background" functions (includes right event, wrong particle -- usually D_s* γ);
    Tested on data sized sample made from other 2/3 of MC

  	φ e νCALC	φ e νMC TRUE	η e νCALC	η e νMC TRUE
  NTags (~3%)	17,577	~17.9K	17,577	~17.9K
  εSL (~4%)	--	15.8%	---	18.7%
  NAll Event	50.7 ± 8.9	46	72.8 ± 10.2	60
  BR(Ds → heν)	(1.83 ± 0.32)%	2.02%	(2.21 ± 0.31)%	2.53%

  Ran over data using background function from all MC:

  	φ e ν	η e ν
  NTags (~3%)	16,103 ± 365	16,103 ± 365
  εSL (~4%)	15.8%	18.7%
  NAll Event	32.2 ± 8.2	38.6 ± 10.8
  BR(Ds → heν)	(1.27 ± 0.32)%	(1.28 ± 0.28)%

  • Definitely inconsistent with Rochester & Syracuse (~2%/2.4%)
  Used all the MC to make "background" functions and tested on same sample:

  	φ e νCALC	φ e νMC TRUE	η e νCALC	η e νMC TRUE
  NTags (~3%)	17,952	~17.9K	17,952	~17.9K
  εSL (~4%)	--	15.8%	---	18.7%
  NAll Event	41.2 ± 10.0	46	47.6 ± 11.7	60
  BR(Ds -> heν)	(1.45 ± 0.35)%	2.02%	(1.42 ± 0.25)%	2.53%

  Two major concerns:

  • Fit function not getting the ideal value (and not getting the right number of background + signal from fit -- can be off by ~10%)
  • Number of MC "true" events lower than expected from input BR and prior efficiency (Note: means efficiency might be lower, which makes data BR worse!)

  Recent update:

  • Changed χ² fit to LL fit -- # signal + background from fit now very close to histogram (within 2-3%)
  • Made 8x data sized samples...

  ---

  
  (6/21/07)

  D_s semileptonic tags

  Summary of procedure

  D_s tagging:
  D_s "clean" modes in MC D_s "clean" mode fit to data 41

  U fit:
  φ e ν U plot over all MC types (charm, cont, radret, tau).

  ---

  
  (6/07/07)

  D_s semileptonic tags

  Recent work:
  • Converted from MN pds files to Cornell EventStore files:
    • Now have both ISR and No ISR files (pds were No ISR only)
    • No difference in E_γ (my tagging parameter) between ISR and No ISR.
    • Cornell does not have multi-body included while MN does (appears insignificant, but observable).
  • Looked into peaking background under E_γ:
    • Effect of D_s mass cut
    • Effect over different types of modes
    • Zoom in on a "bad" mode: ρ η
  • Started looking at D⁰ fitting

  Near future:

  • See what differences exist in other parameters (U, M_bc) between ISR and No ISR cases.
  • Do deeper checks with D⁰ fitting and compare to data
  • Get more complete D_s fits using histogram shape and convoluted functions

  ---

  
  (5/31/07)

  D_s semileptonic tags

  Recent work:
  • Comparing Photon energy resolutions (Note: Pete gets 5.62 +/- 0.06 MeV for both)
  • Big file with all E_γ plots for comparisons
  • Background for non-D_s D_s* and for D_s D_s* events
  • My recoil mass plots, emulating Pete's procedure

  ---

  
  (5/24/07)

  D_s semileptonic tags

  Recent work:
  • Solved MC mystery
  • Now have good E_γ plots
  • Fixed lab frame/beam CM frame issue
  • Added η' e ν
  • Went through η e ν U plots with Chul Su-style modes
  • Loosened D_s mass and M_bc pre-selection cuts to 1920-2015 MeV and 1980-2100 MeV, respectively
  • Fixed issue with E_γ boost (was using PDG D_s* mass instead of reconstructed)
  • Some D_s modes not in MC, or not tagged as such despite being in DECAY.DEC: φ π π π, K*⁰ K*⁺ π⁰
  • E_γ resolution difference with Pete: My σ = 7 MeV; Pete's = 5.5 MeV
    • Different samples?
    • runOnNewPass2 vs. setup_analysis?
  • Looked over E_γ plots by mode
  • Looked into different tagging using lorentz invariants directly
  • Looked into Recoil Mass inconsistencies; possibly still too tight D_s mass
  Near future:
  • D⁰* -> D⁰ γ tagging count, using histogram shape instead of function
  • Build infrastructure to run at Cornell

  ---

  
  (4/12/07)

  D_s semileptonic tags

  Current issue, probably with MC tagging.

  ---

  
  (2/8/07)

  D_s semileptonic

  Mode	# original MC events	# new DTag MC events (1/2 sample -> x2)
  φ π	68	90
  K* K	91	106
  Ks K	73	66

  ---

  
  (2/1/07)

  D_s semileptonic

  E_γ OR cuts

  ---

  
  (12/18/06)

  D_s semileptonic

  Boost while fixing p and E

  ---

  
  (12/14/06)

  D_s semileptonic

  E_γ fits:
  Background
  Everything
  Signal
  

  Procedure:

  • Fit background "region" (below 110 MeV and above 160 MeV) to f(x) = y₀ + A * xⁿ
  • Fixed those background parameters and added fit for gaussian + spread function (spread not convoluted)

  Results:

  Hypothesis	# in fit	# in MC	Fraction off
  Ds*	107,192	104,245	+2.8%
  Swap	96,017	104,245	-7.9%
  Average	101,605	104,245	-2.5%

  Notes:

  • Background peaks slightly (and broadly) in signal region. This has been isolated as being due to true γ + "bad" D_s (only have mass cut of 1940 MeV to 1995 MeV) {see below}
  • Because of the above point, the peak tends to fit slightly high relative to the signal peak.
  • Because of the non-convolution, the spread doesn't extend to the entire signal region.

  Peaking background:

  • Subset of background with MC good D_s and "bad" γ (not from D_s* or not real γ) {solid} and MC good γ with "bad" D_s {dashed} for the swap hypothesis and the D_s* hypothesis. Note that this is a relatively small subset of all background (see, e.g., the y-axis scale).
  • A plot of the D_s mass to see if there's a peak indicating D_s mesons with alternate tag modes. It doesn't look like there are alternate tag modes not accounted for, but there might be a soft peak there.
  • The total background with (pink) and without (dotted red) MC determined D_s* daughter γ.

  Next tagging questions:

  • Would a histogram fit work better than a function fit? (Try in D⁰* -- can look at data and E_γ shape should be similar)?
  • Is Pete's method better than ~10% (systematics probably lower)?

  ---

  
  (12/12/06)

  D_s semileptonic

  Full E_γ plot
  Signal part of E_γ plot

  ---

  
  (12/07/06)

  D_s semileptonic

  Example "complicated" E_γ fit (only bottom converged)
  Signal portion of E_γ fit. Total fit events: 17,700. Total MC count: 8,100.

  ---

  
  (12/05/06)

  D_s semileptonic

  Trying to get # tags from different variables (recoil mass, M_bc, E_γ): Current tag fit attempts

  ---

  
  (11/30/06)

  D_s semileptonic

  M_bc plots

  ---

  
  (11/28/06)

  D_s semileptonic

  U vs. cut variables

  ---

  
  (11/16/06)

  D_s semileptonic

  Initial attempt to duplicate Pete's results

  ---

  
  (11/14/06)

  D_s semileptonic

  Testing hybrid variables

  ---

  
  (11/9/06)

  D_s semileptonic

  Current fit procedure results

  Recoil Mass vs. various D_s* parameters

  Candidates per event

  ---

  
  (11/7/06)

  D_s semileptonic

  Looking into # (D_s+γ) tags for denominator of BR and # (D_s+γ+semileptonic) events for numerator (efficiency corrected)

  Getting # (D_s+γ) tags

  ---

  
  (10/30/06)

  D_s semileptonic

  D_s* exploration plots

  ---

  
  (10/26/06)

  D_s semileptonic

  D_s* exploration plots

  ---

  
  (10/24/06)

  D_s semileptonic

  Overview

  ---

  
  (10/17/06)

  D_s semileptonic

  Efficiency Review

  D_s Effect of D_s cuts

  Ds Mode	ε * BR	εJustin	εBrian
  φ π	17.9%	36.5%	36.7%
  φ ρ	4.1%	8.3%	8.9%
  η π	17.2%	43.8%	43.6%
  η ρ	7.0%	17.9%	15.7%
  η' π	4.8%	28.0%	27.2%
  η' ρ	1.6%	9.6%	9.1%
  K* K	26.7%	40.1%	37.9%
  Ks K	37.6%	54.6%	47.2%

  Total ε * BR = 3.44%

  γ

  Cut	εγ
  None	92.9%
  Not hot	91.6%
  No matched track	90.2%
  In barrel or endcap	87.5%
  E9/E25 OK or E9/E25 > 0.78	84.0% (81.2%)
  97 MeV < Eγ < 182 MeV	79.6%
  Splitoff OK	74.3%
  No π0 rejection	55.2%

  e
  Electron efficiencies

  pe	φ+e+ν	η+e+ν
  <200 MeV	12.6%	3.9%
  200-300 MeV	19.8%	7.4%
  300-600 MeV	61.0%	49.5%
  600+ MeV	6.6%	39.1%

  φ
  Phi cuts, momentum dist. and efficiencies

  ---

  
  (10/10/06)

  D_s semileptonic

  Chul Su comparison: ε_tag+γ+semi / ε_tag+γ

  Semilep Ds mode	Chul Su's figures	My typical cuts (loose)	Standard cuts
  φ+e+ν	21.0% ± 0.4%	28.8% ± 0.8%	20.2% ± 0.9%
  η+e+ν	45.9% ± 0.6%	44.2% ± 0.8%	41.0% ± 0.7%

  φ and η efficiencies, by momentum.

  electron efficiencies, by momentum (unconfirmed).

  ---

  
  (10/3/06)

  D_s semileptonic

  Chul Su semileptonic efficiencies

  Semilep Ds mode	εtag+γ+semi / εtag+γ
  φ+e+ν	21.0% ± 0.4%
  η+e+ν	45.9% ± 0.6%

  My prelim semileptonic efficiencies

  Tagged Ds mode	(φ+e+ν) εtag+γ+semi / εtag+γ	(η+e+ν) εtag+γ+semi / εtag+γ
  φ π	28.0%	35.7%
  φ ρ	20.0%	31.8%
  η π	23.5%	45.1%
  η ρ	--	81.5%
  η' π	29.1%	20.4%
  η' ρ	21.2%	36.4%
  K* K	30.9%	28.3%
  Ks K	29.6%	34.1%

  ---

  
  (9/19/06)

  D_s semileptonic current status

  Two types of examples where kaons miss TQ cuts: Decay in flight (top), and slightly off track reconstruction (side)

  Passing signal events with an MC failure (Red - Blue)
  • Efficiency for a signal event to pass with an MC correct: 6.90%
  • Efficiency for a signal event to pass without any events MC correct: 2.92%
  • Efficiency for a signal event to pass with an MC correct and without at least one MC correct: 3.1% (45% of those with MC correct)

  Particle	Fraction of the time missed	Fraction of the time as the only miss
  e	0%	0%
  φ	31.1%	14.4%
  Ds	12.1%	3.7%
  γ	80.6%	59.2%

  Attempt to find a parameter that separates a passing signal with correct reconstruction vs. passing signal with incorrect reconstruction.

  Near-term goals

  • Fix skimming/efficiency bug!!!
  • Check E₉/E₂₅ for Red/Blue separation
  • Redo efficiency breakdown (including "13 modes"), compare with Chul Su, and isolate any differences
  • Recheck optimal efficiencies

  ---

  
  (8/23/06)

  D_s semileptonic current status

  U plot integrated across all modes Cuts:
  • φ (not in D_s)
  • within 30 MeV
  • Kaon |σ_dE/dx| < 3.0
  • η (not in D_s)
  • Showers Good*
  • E_γ > 30 MeV
  • E_γ^barrel > 50 MeV
  • |σ_η| < 3.0
  • γ (not in D_s)
  • Shower Good*
  • 105 MeV < E_γ < 177 MeV {kinematics: (141 ± 27) MeV}
  • e
  • f with RICH > 0.9
  • D_s
  • 2005 MeV < M_bc < 2075 MeV {kinematics: 2040 MeV / (2047 ± 26) MeV}
  • -130 MeV < ΔE < -30 MeV {kinematics: -70.5 MeV / (-77 ± 27) MeV}
  • 1940 MeV < M_Ds < 1995 MeV {1968.5 MeV}
  • Daughter φ within 10 MeV
  • Daughter K* (neutral or charged) within 75 MeV
  • Daughter ρ within 150 MeV
  • Daughter π⁰ within 3 σ plus standard and splitoff
  • Daughter η within 3 σ plus standard and splitoff
  • Daughter K_s within 3 σ
  • Daughter η' within 10 MeV (π π η) or 30 MeV (ρ γ)
  • Underlying tracks:
    • |&sigma_dE/dx| < 3.5
    • |z₀| < 5 cm from beamspot
    • |r₀| < 5 mm from beamspot
    • Hit fraction < 0.5
    • Χ² < 1000
    • |cos θ| < 0.93
  * - Good showers are defined as:
  • Not hot
  • E₉/E₂₅ O.K.
  • Not matched track
  • Location O.K. (endcap or barrel)

  ---

  
  (8/23/06)

  D_s semileptonic

  post-FSR/Brem and alternate signal mode fixes (using φ e ν)

  Ds Tag Mode	Total Background	Possibly confusing background (within 50 MeV of U=0)	Signal events	εAll good	εEvent pass
  φ π	5	2	66	9.7%	15.5%
  φ ρ	1	0	17	2.4%	5.7%
  η π	3	0	26	10.0%	14.6%
  η ρ	0	0	54	5.1%	8.1%
  η' π	1	0	19	2.7%	3.2%
  η' ρ	0	0	11	1.2%	2.9%
  K* K	? (24)	1 (14)	91	15.3%1	22.5%
  Ks K	? (9)	0 (3)	72	18%	22.5%

  Current status shown in a U = E_miss - p_miss plot.

  ---

  
  (8/09/06)

  D_s semileptonic

  FSR/Brem. and "signal background" events

  Ds Tag Mode	FSR/Brem	signal background	true background	total background events
  φ π	16	3	3	22
  φ ρ	2	10	1	13
  η π	4	0	2	6
  η ρ	12	9	0	21
  η' π	2	0	1	3
  η' ρ	3	4	0	7
  K* K	21	16	2	39
  Ks K2	8	1	1	10
  Sum	68	43	10	121
  Percentage of total	56%	36%	8%	100%

  ---

  
  (7/26/06)

  D_s semileptonic

  Chul Su cut ε, isolation ε, sequential σK 97.0% 97.0% z0 95.7% 94.5% r0 93.8% 91.6% chi2 99.9% 91.6% hit fraction 87.5% 83.6% base cuts 99.7% 83.6% mass * 79.4%

  My cut ε, isolation ε, sequential σK 97.0% 97.0% z0 96.9% 95.5% r0 96.1% 94.1% chi2 97.0% 92.6% hit fraction 100% 92.6% base cuts 99.7% 92.6% mass * 92.6%

  ---

  
  (7/19/06)

  D_s semileptonic

  Current total U plots (adding all modes)
  Poor man's kinematic fit doesn't seem to improve much: No kin. fit followed by kin. fit on D_s using pdg mass constraint
  

  Current issues:

  • Some peaking background accounted for, but not all (~1/2 ?)
  • Slight difference in ε with Chul Su: 21.0% (φ e ν) and 46% (η e ν) vs. 30% (φ e ν) and 32% (η e ν) for semileptonic efficiency given that D_s and γ were both found.
  • Possible issues with D_s* -> π⁰ D_s and FSR?

  ---

  
  (7/12/06)

  D_s semileptonic

  MC true and MC false plots of E_miss vs. U
  Effect of M_Ds cut on sidebands: without cut and with cut
  M_Ds vs. U, MC true and MC false

  ---

  
  (7/5/06)

  D_s semileptonic

  Recent Plots (all plots φ+e+ν, not η+e+ν):

  • Current status of U plots.
    Blue = all particles MC tagged as correct; Black = total; Red = event true, but some particle MC tagged incorrectly
  • Non-MC true event U plots (black - red)
  • Recoil Mass, by mode
  • Total Event Extra Energy, by mode
  • QQId of extra energy particles & parents
  • Extra Energy, by shower and type

  Current Efficiencies:

  Ds Tag Mode	εφ e ν
  φ π	8.9%
  φ ρ	1.7%
  η π	10.1%
  η ρ	4.3%
  η' π	5.9%
  η' ρ	1.2%
  K* K	7.5%
  Ks K2	5.8%

  Near-term to do:

  • Investigate new tag modes & cause of background (using Peter's DTag)
  • See if extra energy will be a viable cut (using added MC info)

  ---

  
  (6/21/06)

  D_s semileptonic

  Summary:

  • Looked at extra tracks ( made new cut)
  • Looked at extra energy (no cuts yet; potential)
  • Looked at improperly tagged modes (no cuts yet; potential)
  • Looked at various q² info:
    • true q² at creation (from QQ info)
    • #phi e #nu + #phi tags q²
    • #phi e #nu + #phi #pi q²

  ---

  
  (6/14/06)

  D_s semileptonic

  Higher η e ν vs. φ e ν efficiency: Electron Momenta

  Guided by need for maximizing efficiency:

  • "No" cuts¹
  • Current cuts (at worst, 90% the efficiency of "No" cuts {η}; usually 99%)
  ¹ - No cuts:
  • Default D_s (too tight for K and ρ)
  • Passes electron cut (Chul Su's; effectively same as E/p)
  • γ: good SQ and 105-170 MeV
  • φ: "negation" PID (K PID = not π, not e)
  • η: Standard CLEO with accidentally overly tight pull mass (2.5)
  Concerns:
  • This is ~15M events (200 pb^-1 should have ~2M events). Might need to be cleaner.
  • Underweighted continuum (~10 additional background/mode; more w/ η tags)
  To do:
  • Run over larger MC sample to ensure no efficiency oddity (have 2X as much, generating 3X as much as last week)
  • Get more quantitative feel for the effect on different q² bins (e.g. High q² is generally cleaner, but do the cuts enhance this or make it less dramatic relative to other bins?).
  • See if further cut improvements can be made (e.g. Can get minimal background for 50% efficiency hit, but probably not worth it; is there an in-between?).
  • See how well the fits work at existing & future cut levels.
  • See what events make up the background.

  ---

  
  (6/7/06)

  D_s semileptonic

  Efficiency oddity:

  Ds Tag Mode	εφ e ν (ε x BR1)	εη e ν (ε x BR1)	εη e ν / εφ e ν3
  φ π	9.1% (2.2%)	11.8% (2.3%)	1.30
  φ ρ	1.65% (0.4%)	2.39% (0.5%)	1.45
  η π	11.31% (2.2%)	18.26% (2.8%)	1.61
  η ρ	4.48% (0.9%)	4.71% (0.7%)	1.05
  η' π	6.05% (0.5%)	8.51% (0.6%)	1.41
  η' ρ	1.24% (0.1%)	1.78% (0.1%)	1.43
  K* K	7.53% (2.5%)	11.04% (2.9%)	1.47
  Ks K2	5.92% (2.0%)	9.86% (2.7%)	1.67

  Notes:
  ¹ This BR is the combined BR of the D_s daughters to observable modes, but not the D_s itself (e.g. it counts η -> γ γ, but not D_s -> η π). The BR to all of the focus tag modes is ~3.5%, except for η π, which is about half that.
  ² These efficiencies may be off by a factor of 2 relative to Brian's.
  ³ From statistics, I'd expect roughly +/-1% in ε

  ---

  
  (5/31/06)

  D_s semileptonic

  Overall efficiency: ε ≈ ε_e * ε_φ/η * ε_γ * ε_Ds

  ε_e = 95% (left track) x 76.6% (pass PID) = 72.8%

  ε_γ = 93.4% (left shower) x 87.4% (pass SQ) x 93.0% (pass energy cut: 105-177 MeV) = 75.9%

  ε_Ds:

  Mode	Primary Ds	Secondary Ds
  φ π	41.3%	43.5%
  K* K	38.2%	38.8%
  Ks K	29.3%	29.3%
  η π	53.4%	54.2%

  ε_η = 52.6% (not broken down; standard cuts)

  ε_φ = 50.6% (both K leave tracks) * 92.3% (Justin's TQ) * 99.7% (negation PID) = 46.6%

  Final ε_{η e ν} : ~11%

  Final ε_{φ e ν} : ~10% ?

  Example of final U plot (MM similar in S/B): φ e ν + (φ π / K* K / K_s K)

  ---

  
  (5/17/06)

  D_s semileptonic

  Looking into efficiencies for later q² adjustments.

  Different K cuts going into the φ:

  • φ mass using 9 different cuts
  • Same, but only in events that are MC tagged to have a φ

  Different e cuts?:

  • Current efficiency is 74% (eta e nu) or 84% (phi e nu) (+/- 3%) assuming a track is left (~95% efficiency regardless of mode).
  • Chul Su's "f" parameter
  • Just E/p
  π has ~95% left tracks, ~97% passed TQ, ~95% passed PID.

  ---

  
  (5/2/06)

  D_s semileptonic

  Plan:
  • Reinvestigate efficiencies
  • Make some proc changes for better η support, more e⁺e^- control, more π⁺/π^- control, and μ support
  • Look at events split into different q² regimes (efficiencies, varying cuts
  (D_s -> φ e ν) + (D_s -> φ π) + γ
  Maximum possible efficiency within φ -> K+K- events is ~25% (efficiency for each of 7 particles to leave a reconstructable object: 4 K, 1 e, 1 π, 1 γ).
  Efficiency with my original cuts is ~5% (same as Chul Su's)
  Possible culprits:
  • Kaon TQ (relaxing can add ~40%-50% more "potential" signal, dropping altogether can add ~2x "potential" signal)
  • Photon SQ (has efficiency of ~70%; probably not much can be done here)
  • Photon π⁰ rejection (efficiency ~80%; should be dropped)
  • Electron PID (has efficiency of ~80%; haven't studied much yet)
  • Kaon PID, π PID, and π TQ all 95%+
  • Cuts on parent particles (D_s ΔE, M_bc, φ mass; naive efficiency of ~80-90%)
  Check out φ Plot of φ mass.
  Ignoring K TQ cuts:

  φ mass cut	εProper Event	εProperly tagged
  10 MeV	91.3% (+0%)	81.9% (+0%)
  12.5 MeV	92.1% (+.9%)	86.6% (+5.7%)
  15 MeV	92.1% (+.9%)	87.4% (+6.7%)
  17.5 MeV	94.5% (+3.5%)	89.8% (+9.6%)
  20 MeV	95.3% (+4.4%)	90.6% (+10.6%)
  30 MeV	96.9% (+6.1%)	95.3% (+16.4%)

  ---

  
  (4/11/06)

  D* producer update

  D* code has been uploaded into CVS; documentation still to be rewritten, but naive efficiencies from CLEO talk confirmed:

  Mode	Predicted	"Actual"
  D*0 -> D0 π0	34%	37%
  D*+ -> D0 π+	25%	26%
  Ds* -> Ds γ	18%	21%

  Note: Only D⁰ -> K π and D_s -> φ π

  Return to D_s -> φ e ν, etc.

  When last I looked at D_s -> φ e ν, I had found that loosening the kaon hit fraction cut to 0.1 could increase the efficiency by a factor of 1.4. S/B is probably low enough anyway, but just to get restarted, I looked at whether or not a "smarter" hit fraction cut could be made:
  Hit fraction of K from #phi in four different momentum regions
  Possible reference: Momentum distribution of K from #phi

  ---

  
  (4/4/06)

  Ntuple Maker

  I made an Ntuple Maker to make the class and definition files for ntuples with arrays.

  ---

  
  (3/21/06)

  D* Producer

  Remaining issues:
  • Do a "thrice-over" on D* class/producer code
  • Eliminate Storage Helper (possibly not worth the effort)
  • Add example .tcl files (with extra-tight cuts) and plots to webpage
  • Add code notes/explanations to separate web page (after "thrice-over")
  • Convince myself that split-off works (or fix split-off)
  • Look into "--> creating ../lib/libDStar.a.version" problem (probably not worth the effort)
  • Reoptimize D_s* cuts
  • Add new functionality (e.g. # Min RICH γ) to documentation
  • Ensure all DTag cuts are still O.K.
  • Check dE/dx of 3.0 vs. 4.0
  Done, but check in final version:
  • .tcl cuts all work as expected
  • Producer runs at Cornell
  • OtherSideShowers/OtherSideTracks functions work

  ---

  
  (3/14/06)

  D* Producer

  D* user documentation

  ---

  
  (3/7/06)

  D* Producer

  Current issues:
  Super-Extra, Really Irritatingly Large:

  • ΔM discrepancy: D* producer vs. Brian's (more below)
  Major:
  • Test every π⁰, π⁺, and γ cut {essentially done}
  • Run my producer at Cornell (currently have only tested at MN) {essentially done}
  Minor:
  • Make a more consistent naming scheme?
    (e.g. D* daughter calls are:     gamma(), thepi0(), thepion() )
  • Give user more π⁰ and π⁺ control?
  • Clean up dirty code (outdated output statements, change comments)
  • Figure out what to do with spurious storage helper
  • Write up page on how to use
  • Give sample .tcl file with good starting cuts (by default, cuts are very loose)
  • Make ΔM cut asymmetric like M_bc and ΔE.
  • Double-check OtherSideShowers/OtherSideTracks functions
  • Give user split-off control (e.g. param DStarProd UseSplitoff true) {Test this}
  • Fix/Find "--> creating ../lib/libDStar.a.version" error
  • Switch to new beamspot technique
  ΔM discrepancy
  True D⁰
  True π⁰
  D* mass for high ΔM
  Cut testing
  Cut Plots

  ---

  
  (2/28/06)

  D* Producer

  What it does:
  
  • Automatically reconstructs various D* modes:
    • D*0_SC     (for π⁰ and γ modes)
    • D*0_NS     (for π⁰ and γ modes)
    • D*0_SC_pi0
    • D*0_SC_gamma
    • D*0_NS_pi0
    • D*0_NS_gamma
    • D*+     (for π⁰ and π⁺)
    • D*+_pi0
    • D*+_pi+
    • D*+_gamma
    • Ds*     (for γ only)
    • Ds*_pi0
  • Allows various cuts to be made in .tcl file (raw):
    • D*'s M_bc
    • D*'s ΔM
    • D*'s ΔE
    • D*'s constituent D mass
    • D*'s mass
    • Various π⁰ cuts
    • Various π⁺ cuts
    • Various γ cuts
    • Allow specific D modes used to make D*:     param DStarProd AllowedDModes 0 200 1100
  • Easy (hopefully) extraction:

    FAItem iDsListItem;
    extract(iFrame.record(Stream::kEvent), iDsListItem, "Ds*");
    
    for (DStarList::const_iterator iDsItr = (*iDsListItem).particle_begin();
    iDsItr != (*iDsListItem).particle_end();
    ++iDsItr)
    {
        const DStar& iDStar = (*iDsItr).particle();
        const DTag& iD = iDStar.taggedD();
        const NavShower& iGamma = iDStar.gamma();
    
        const double deltaM = iDStar.deltaM();
    }

  Current issues:
  Major:

  • ΔM discrepancy: D* producer vs. brian's
  • Test every π⁰, π⁺, and γ cut
  • Run my producer at Cornell (currently have only tested at MN)
  Minor:
  • Make a more consistent naming scheme?
    (e.g. D* daughter calls are:     gamma(), thepi0(), thepion() )
  • Give user more π⁰ and π⁺ control?
    (same as DTag π⁰ and π⁺, allow different, etc.)
  • Clean up dirty code (outdated output statements, change comments)
  • Figure out what to do with spurious storage helper
  • Write up page on how to use
  • Give sample .tcl file with good starting cuts (by default, cuts are very loose)
  • Make ΔM cut asymmetric like M_bc and ΔE.

  ---

  
  (12/20/05)

  Looking at high cos(θ) tracks

  cos(&theta) when z₀ is smaller than 2 cm

  ---

  
  (12/13/05)

  D_s -> φ e ν

  Investigation of Kaon TQ cuts

  Kaon track quality parameters for reconstructed tracks that are MC tagged as kaons from phi.

  Cuts	% Kaons that pass	%2	%4	Relative gain over standard
  Standard	83.6%	69.9%	48.8%	1
  Hit Fraction ≥ 0.1	91.0%	82.8%	68.6%	1.41
  Hit Fraction ≥ 0.1 z0 ≤ 0.1 r0 ≤ 0.01 Χ2 ≤ 10	93.5%	87.4%	76.5%	1.57

  ---

  
  (12/06/05)

  D_s -> φ e ν

  Current status (using φ π, E_cm = 4160 MeV):
  σ(D_s D_s*) ≈ .83 nb
  BR(φ π) = 3.6%, BR(φ e ν) = 2%
  Assuming 400 pb^-1, should have 3.3 * 10⁵ D_s D_s* events.
  1/2² from φ -> K⁺K^-
  5% efficiency
  # tagged events = 2 (3.3 * 10⁵) (.036) (.02) (.5)² (.05) = 6 events

  Assuming that adding more modes and increasing efficiency will increase by a factor of 6, that gives 36 events -> 17% on BR +/-.
  Current value is 25%, but Γ(φ l ν) / Γ(φ π) is ~10%.

  Adding modes

  Mode	εDs producer	BR/BR(φ π)	εprod * BR/BR(φ π)	εDs* side	εDs side
  φ π	37%	1	1	4.26%	5.66%
  φ ρ	11%	1.86	0.55	0.96%	1.2%
  η ρ	14%	2.4	0.91	1.42%	2.04%
  K* K	39%	1.25	1.32	3.97%	5.01%
  Ks K	58%(40%)	0.7	1.10	5.17%	6.69%

  
  

  ---

  
  (11/22/05)

  D_s -> φ e ν

  Corrected U = E_miss - p_miss plot for the primary side and the secondary side.

  ---

  Efficiency investigation

  Breakdown of efficiencies at the basic (observable particles) level:

  Particle type	Has a track	Passes TQ	Passes PID
  Kaon (1)	77.2%	83.6%	97.2%
  Kaon (4)	32.6%	48.8%	89.3%
  Electron	92.9%	96.9%	77.9%
  Pion	91.1%	98.6%	100%?

  Particle type	Has a shower	Passes SQ	Passes π0 suppression	Has proper energy
  Ds* Photon	81.3%	92.8%	81.8%	83.2%

  These result in an overall efficiency of 4.6%.
  Look more at the kaon momenta and the efficiency for a kaon to leave a track.

  ---

  Currently obtained efficiencies:

  Side with the φ π	Pass all cuts	Pass all cuts with everything tagged correctly
  Primary Ds	5.66%	4.04%
  Ds*	4.26%	3.68%

  ---

  
  (11/15/05)

  D_s -> φ e ν

  U = E_miss - p_miss and missing mass² plots when the D_s decays to φ π on the primary side and the secondary side.

  Difference between U when summing all energies/momenta vs. when using the reconstructed particles (D_s, etc.) for primary side and the secondary side.

  ---

  
  (10/11/05)

  D_s -> φ e ν

  Initial plots of missing mass² and E_missing - p_missing

  Given:

  • D_s is reconstructed via φ π
  • In addition to the D_s's φ, there is another φ that shares no tracks.
  • There is exactly one electron.
  • There is a D_s* that can be reconstructed from the D_s.
  • There are exactly 6 "valid" tracks (goes through origin, etc.)

  ---

  
  (9/13/05)

  Efficiencies for reconstructing D_s* by mode

  These are the efficiencies for events that are truly from D_s* where the D_s has been properly reconstructed. The following cuts are made:
  
  • M_bc for the D_s is in the "box, not peak" region (2021 MeV < M_bc < 2073 MeV, but not 2044-2050 MeV)
  • ΔE for the D_s is between -100 MeV and -40 MeV
  • There is a "good" shower (this accounts for ~30% reduction in efficiency)
  • M_bc for the D_s* is between 2036 MeV and 2046 MeV
  • ΔE for the D_s* is between -100 MeV and -40 MeV

  Ds Mode	ε	S/B
  φ π	65%	1.7
  φ ρ	46%	0.6
  η π	60%	1.1
  η ρ	48%	0.6
  η' π	47%	1.1
  η' ρ	42%	0.6
  Ks K	55%	1.2
  K* K	53%	0.8

  
  Note: The S/B can be improved somewhat for the various modes via a M_Ds* - M_Ds, or otherwise tighter cuts. At this time, I have suspicions as to why, but I have not worried about it yet.

  ---

  
  (9/6/05)

  Adding ΔE and M_bc cuts on the D_s*

  Note: These are all at a beam energy of 4160 MeV and only include φ π decays of the D_s

  Reconstructed D_s* ΔE for MC true vs. false D_s*.
  Reconstructed D_s* M_bc for MC true vs. false D_s*.

  M_Ds* - M_Ds after cutting on the ΔE and M_bc of the D_s*.

  With no ΔM cuts, the efficiency of constructing the D_s* from the D_s is ~65%; the signal to background is ~1.7

  ---

  
  (8/30/05)

  M_Ds* - M_Ds

  The mass difference between the reconstructed D_s* and its daughter D_s, where:
  
  • ΔE ∈ ( 70 ± 30 ) MeV
  • Showers follow:
    • no track match
    • not hot channels
    • E₉/E₂₅ OK
    • in the "good" region
    • not π⁰ suppressed.
  • M_bc "box" is taken to be ( 2047 ± 26 ) MeV.
  • M_bc "peak" is taken to be ( 2047 ± 3 ) MeV.
  Also, the plot for M_bc in the "box not peak", broken down by type of charm event.

  ---

  
  (8/11/05)

  More preliminary results with Brian's DTag producer

  Δ E and M_bc plots.

  ---

  
  (8/9/05)

  Using Brian's DTag producer; preliminary results

  Mass difference between D_s* and D_s for all modes and any M_bc / Δ E.
  M_bc for φ π

  ---

  
  (7/26/05)

  Additional η and other modes investigation

  Not much to show -- perhaps something is wrong? Only 26% efficiency!

  ---

  
  (7/21/05)

  D_s* -> D_s γ Investigation

  π⁰ efficiencies:

  Efficiency	All π0's	"signal" π0's
  εNavPi0	38.1%	57.2%
  εreconstruct	68.4%	69.3%

  The two photon invariant mass in broad scale and narrow scale.

  Percentages of photons from specific parent particles that survive my current π⁰ cuts (in all events):

  Parent	ε
  π0	34.8%
  Ds*	73.7%
  η	95.5%

  Some sample D_s* reconstructed shower spectra, after all cuts (including π⁰):
  φ π
  η π
  η' ρ

  ---

  Future plans

  • Redo lots of code to accomodate new running environment (no more Cornell -> MN transfers, desire for more cut wiggling, etc.).
  • Investigate differences in Brian's efficiencies vs. my efficiencies (look at PID efficiencies).
  • Redo code to start using Brian's D_s tag processor
  • Do a "poor man's" D_s -> μ ν to get an idea of how effective using the D_s* can be in practice.
  • Investigate D_s* -> D_s π⁰
  • Look into value of adding some new modes: η -> 3 π, possibly others
  • Look into possibility for D_s -> K⁺ K_S/K_L interference analysis (analogous to Steve Stroiney's D -> π⁺ K_S/K_L analysis)

  ---

  
  (7/14/05)

  D_s* -> D_s γ Investigation

  I've been trying to compare my results to Brian's in a variety of ways, to establish that I'm doing things correctly. Some early (moderately investigated) results:

  Particle	ε	BR of tagged mode
  φ	22.7%	50%
  η	21.4%	40%
  η'	6.3%	18%

  My efficiencies and S/B vs. Brian's (note: I accidently loosened my η cuts slightly from my "normal" sample)

  Ds decay mode	ε normal	S/B	ε loose	S/B	ε Brian	S/B
  φ π	35.2%	3.5	42.6%	2.1	40%	5.4
  φ ρ	8.2%	0.5	10.8%	0.3	10%	0.9
  η π	32.2%	0.4	36.1%	0.5	41%	0.4
  η ρ	10.8%	0.3	11.1%	0.4	18%	0.24
  η' π	10.4%	0.9	10.4%	0.9	29%	2.5
  η' ρ	3.3%	0.2	2.7%	0.2	11%	0.4

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  (7/12/05)

  D_s* -> D_s γ

  Real π⁰ before and after suppression.

  D_s* photons before and after suppression.

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  (7/7/05)

  Updated D_s* -> D_s γ

  D_s* photons compared to all photons

  Pi0 suppression effects: All showers compared to Only "good" showers

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  (7/5/05)

  D_s* -> D_s γ

  Shower energy plot in D_s D_s* events, reconstructed when the initial D_s decays via φ π

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  (6/14/05)

  K -> μ ν mystery

  I noticed of μ had momentum corresponding to that of K -> μ ν with the Kaon at rest. This becomes clear with the R vs. Z distribution.

  PID Wrap-up

  I finished getting efficiency vs. momentum spectra for a variety of different cuts for each of the 5 charged particle types. Here's a sampling of the
  Pion efficiency with Kaon fakes
  and the
  Kaon efficiency with Pion fakes

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  Old results