Thrust cut                                                                        Kenji Hamano

Last modified : Oct 28, 2005                                              Back to Home Back to privious page

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R16b skims Run3 was used.
Data luminosities:

	luminosity	# events	# files
OnPeak	30.630 fb-1	17527801/438622047	877
OffPeak	2.394	659867/31451100	33

MC luminosity is adjusted to 30 fb-1

MC mode	cross section	selection rates	# events	# files
BpBm (1235)	0.525e6 fb	23854196/86492000	4343795	218
B0B0bar (1237)	0.525e6	17081965/61158000	4399112	220
ccbar (1005)	1.30e6	6127861/57700000	4141882	208
uds (998)	2.09e6	5639210/124040000	2850520	143
tautau (3429)	0.94e6	544465/69852000	219806	11

Example of calculatin of # events:
      BpBm: 0.525e6*30*23854196/86492000 = 4343795

Bhabha veto is applied.
KMicroNotPionGTL is applied.
FitDprob > 0.01 and FitBprob > 0.01 are applied.


cosine of the angle between thrust axis of Dl and nonDl
cosDlnonDl (D0Kpi)
cosDlnonDl (D0Kpi) Signal
cosDlnonDl (D0Kpi) Signal (B->Dlnu only)
cosDlnonDl (DchKpipi)


D0 mass : no thrust cut
Dch mass : no thrust cut
D0 mass : |cosDlnonDl| < 0.88
Dch mass : |cosDlnonDl| < 0.88

A. D0Kpi

D0 mass (D0->Kpi) : MC components : no cut
D0 mass (D0->Kpi) : MC components : |cosDlnonDl| < 0.88

Fractional uncertainty of signal
   Delta_S / S = sqrt[(nSig + nBkg + rho*rho*nBkg*nBkg)] / (nSig)
Setting rho = 0

D mass peak region : 1.864 +- 0.024 : 1.840 GeV < D mass < 1.888 GeV
D mass side band : 1.816 GeV < D mass < 1.840 GeV and 1.888 GeV < D mass < 1.912 GeV
No thrust cut:
   nSig = 125263, nBkg = 471940, Delta_S/S = 0.006169
|cosDlnonDl| < 0.96:
   nSig = 119398, nBkg = 381608, Delta_S/S = 0.005928
|cosDlnonDl| < 0.92:
   nSig = 113723, nBkg = 321612, Delta_S/S = 0.005802
|cosDlnonDl| < 0.88:
   nSig = 107990, nBkg = 278126, Delta_S/S = 0.005754
|cosDlnonDl| < 0.84:
   nSig = 102236, nBkg = 245488, Delta_S/S = 0.005768
|cosDlnonDl| < 0.80:
   nSig = 96666, nBkg = 219108, Delta_S/S = 0.005813

Detailed number of candidates
no thrust cut
nDl plots : |cosDlnonDl| < 0.88

	no cut		|cosDlnonDl| < 0.88
	Peak	Sideband	Peak	Sideband
Bp->Dlnu	17210	433	14950	380
Bp->D*lnu	49519	1186	42769	1039
Bp->D0**lnu	466	13	397	10
Bp->D1**lnu	3242	84	2779	71
Bp->D1H**lnu	2065	37	1771	32
Bp->D2**lnu	1231	35	1059	32
Bp->DPilnu	2087	47	1816	37
Bp->D*Pilnu	1431	27	1217	22
B0->D*lnu	33348	863	28670	749
B0->D0**lnu	914	20	779	15
B0->D1**lnu	3685	92	3135	79
B0->D1H**lnu	2336	55	2007	44
B0->D2**lnu	1908	34	1627	29
B0->DPilnu	4183	130	3636	107
B0->D*Pilnu	1638	33	1378	28
signal total	125263	3089	107990 (86.2%)	2671
non-B	219900	197221	81903 (37.2%)	71270
K mis ID	132862	132488	101948	101716
Pi mis ID	32093	32586	25270	25682
K and Pi not from same D	39131	39401	30545	30789
extra K or Pi from same D	31	50	25	40
lepton mis ID	7006	233	5622	187
lepton not direct from B	20599	654	16274	506
lepton and D not from same B	20318	1520	16539	1257
background total	471940	404153	278126 (58.9%)	231447
Delta_S/S	0.006169		0.005754

B. DchKpipi

D0 mass (Dch->Kpipi) : MC components : no cut
Dch mass (Dch->Kpipi) : MC components : |cosDlnonDl| < 0.88

Fractional uncertainty of signal

Only D mass peak region : 1.869 +- 0.024 : 1.845 < D mass < 1.893
D mass side band : 1.821 GeV < D mass < 1.845 GeV and 1.893 GeV < D mass < 1.917 GeV
No cut
   nSig = 75639, nBkg = 892051, Delta_S/S = 0.013005
|cosDlnonDl| < 0.96:
   nSig = 71978, nBkg = 770507, Delta_S/S = 0.012752
|cosDlnonDl| < 0.92:
   nSig = 68588, nBkg = 680920, Delta_S/S = 0.012622
|cosDlnonDl| < 0.88:
   nSig = 65277, nBkg = 610372, Delta_S/S = 0.012592
|cosDlnonDl| < 0.84:
   nSig = 61834, nBkg = 551900, Delta_S/S = 0.012670
|cosDlnonDl| < 0.80:
   nSig = 58513, nBkg = 502329, Delta_S/S = 0.012799

Detailed number of candidates
nDl plots : no thrust cut
nDl plots : |cosDlnonDl| < 0.88

	no vertexing		|cosDlnonDl| < 0.88
	Peak	Sideband	Peak	Sideband
Bp->D0**lnu	1541	49	1364	41
Bp->D1**lnu	1473	48	1252	41
Bp->D1H**lnu	888	23	774	17
Bp->D2**lnu	2254	78	1944	65
Bp->DPilnu	6520	200	5637	171
Bp->D*Pilnu	604	14	529	13
B0->Dlnu	29963	861	25926	723
B0->D*lnu	25814	764	22217	643
B0->D0**lnu	732	20	620	17
B0->D1**lnu	705	22	583	21
B0->D1H**lnu	484	9	407	8
B0->D2**lnu	1138	33	991	30
B0->DPilnu	3239	114	2787	96
B0->D*Pilnu	284	7	246	7
signal total	75639	2242	65277 (86.3%)	1893
non-B	270488	251628	114536 (42.3%)	105654
K miss ID	112996	112855	89052	88757
Pi miss ID	206320	207291	165955	166521
K Pi not from same D	260515	260767	208683	208841
extra K or Pi from same D	42	39	38	33
lepton miss ID	6247	211	4848	157
lepton not direct from B	16681	593	12679	464
lepton and D not from same B	18762	1256	14581	1031
background total	892051	834640	610372 (68.4%)	571458
Delta_S/S	0.013005		0.012592

When you do D mass sideband subtraciton, the uncertainty on signal may be
      Delta_S/S = qsrt(S_peak + B_peak + S_side + B_side)/(S_peak - S_side)

D0Kpi	S_peak	B_peak	S_side	B_side	uncertainty
no cut	125263	471940	3089	404153	0.0082032
|cosDlnonDl| < 0.96	119398	381608	2932	323204	0.0078089
0.92	113723	321612	2806	269657	0.0075850
0.88	107990	278126	2671	231447	0.0074777
0.84	102236	245488	2524	202894	0.0074588
0.80	96666	219108	2391	180300	0.0074889

DchKpipi	S_peak	B_peak	S_side	B_side	uncertainty
no cut	75639	892051	2242	834640	0.0183024
|cosDlnonDl| < 0.96	71978	770507	2123	721253	0.0179134
0.92	68588	680920	2007	637638	0.0177021
0.88	65277	610372	1893	571458	0.017632
0.84	61832	551900	1788	517354	0.017726
0.80	58513	502329	1673	471165	0.0178871

Conclusion
Optimum point may be around |cosDlnonDl| < 0.86, but since no big difference between 0.84 and 0.88, a bit looser 0.88 seems to be the best choice.

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