evtSelection

Event Selection using Run2 Kenji Hamano

Last modified : Mar 21, 2007 Back to Home Back to privious page

Event Selection

R16b skims Run2 was used.
On Peak data luminosity: 59.4 fb-1

All numbers are luminosity normalised to OnPeak data

Dp = number of OnPeak data candidates in the D mass peak region
Ds = number of OnPeak data candidates in the D mass sideband region

Sp = number of signal candidates in the D mass peak region
Bp = number of backgorund candidates in the D mass peak region using OffPaek data
Ss = number of signal candidates in the D mass sideband region
Bs = number of backgorund candidates in the D mass sideband region using OffPaek data

Err = uncertainty on signal after D mass sideband subtraction using OffPaek data
= sqrt(Sp + Bp + Ss + Bs)/(Sp - Ss)

Bp (MC) = number of backgorund candidates in the D mass peak region using ccbar, uds and tautau MC.
Bs (MC) = number of backgorund candidates in the D mass sideband region using ccbar, uds and tautau MC.

Err (MC) = uncertainty on signal after D mass sideband subtraction using ccbar, uds and tautau MC.
= sqrt(Sp + Bp (MC) + Ss + Bs (MC))/(Sp - Ss)

Decay Chain Fitting by Hulsbergen

1. BToDlnu skim + D reconstruction mode selection

Select only : D0 -> K Pi, and D+ -> K Pi Pi

	D0	D+	Sum
Dp	3451070	4159486	7610556
Ds	2944833	3817929	6762760
Sp	285073	170819	455892
Bp	3166004	3844788	7010793
Ss	14535	8109	22645
Bs	2916710	3623976	6540690
Err	0.009338	0.01699	0.008645
Bp (MC)	2641764	3773788	6415553
Bs (MC)	2408973	3563890	5972860
Err (MC)	0.008550	0.01685	0.008279

2. Tihghter Kaon Selection

Use KMicroNotPion selector

	D0	D+	Sum
Dp	1415443	4159481	5574924
Ds	915899	3817921	4733820
Sp	278235	170819	449054
Bp	1129791	3844788	4974579
Ss	13848	8109	21957
Bs	884724	3623976	4508700
Err	0.005744	0.01699	0.007387
Bp (MC)	996013	3773788	4769802
Bs (MC)	762145	3563890	4326040
Err (MC)	0.005416	0.01685	0.007241

Plots :
D mass with OffPeak data
D mass with qqbar MC

Lepton momentum with OffPeak (3D binned)
D momentum with OffPeak (3D binned)
cosBY with OffPeak (3D binned)

Lepton momentum with OffPeak (Bin by bin, D0)
Lepton momentum with OffPeak (Bin by bin, Dch)
D momentum with OffPeak (Bin by bin, D0)
D momentum with OffPeak (Bin by bin, Dch)
cosBY with OffPeak (Bin by bin, D0)
cosBY with OffPeak (Bin by bin, Dch)

Electron only
    Err = 0.009772
    Err (MC) = 0.009241

D mass plots :
D mass with OffPeak data
D mass with qqbar MC

Muon only
    Err = 0.01125
    Err (MC) = 0.01144

D mass plots :
D mass with OffPeak data
D mass with qqbar MC

3. D and B vertexing

Tihghter Kaon Selection is applied.
D and B vertexing using TreeFitter

Err (D0 only)	no cut	D prob > 0.0001	0.001	0.01	0.1
no cut	0.005744	0.005344	0.005294	0.005224	0.005260
B prob > 0.0001	0.005059	0.005051	0.005029	0.004989	0.005053
0.001	0.004979	0.004979	0.004970	0.004940	0.005013
0.01	0.004870	0.004870	0.004870	0.004863	0.004950
0.1	0.004815	0.004815	0.004815	0.004815	0.004889

Err (D+ only)	no cut	D prob > 0.0001	0.001	0.01	0.1
no cut	0.016996	0.014602	0.014429	0.014178	0.014062
B prob > 0.0001	0.014156	0.014135	0.014027	0.013827	0.013750
0.001	0.013916	0.013915	0.013887	0.013729	0.013679
0.01	0.013558	0.013558	0.013558	0.013529	0.013549
0.1	0.013241	0.013240	0.013240	0.013240	0.013326

Err (D0 + D+)	no cut	D prob > 0.0001	0.001	0.01	0.1
no cut	0.00738718	0.006407	0.006323	0.006202	0.006151
B prob > 0.0001	0.006177	0.006167	0.006114	0.006018	0.005987
0.001	0.006065	0.006065	0.006051	0.005973	0.005954
0.01	0.005901	0.005902	0.005902	0.005890	0.005900
0.1	0.005761	0.005761	0.005761	0.005761	0.005843

Sp (D0 + D+)	no cut	D prob > 0.0001	0.001	0.01	0.1
no cut	449054	435123	432039	424285	385758
B prob > 0.0001	430717	430146	427671	420432	382648
0.001	426718	426714	425693	418989	381645
0.01	417204	417201	417201	414308	378830
0.1	376526	376524	376524	376524	361481

Best uncertainty is given by D prob > 0.01 and B prob > 0.1
But, since no big difference on uncertainties, we prefer looser cut.
Thus, the best cut is D prob > 0.001 and B prob > 0.01

In case of D prob > 0.001 and B prob > 0.01 :

	D0	D+	Sum
Dp	969164	2259010	3228180
Ds	530827	1971310	2502140
Sp	262733	154468	417201
Bp	719464	2066000	2785470
Ss	10387	4767	15154
Bs	517713	1894350	2412060
Err	0.004870	0.01355	0.005901
Bp (MC)	678320	2056620	2734940
Bs (MC)	483935	1888650	2372590
Err (MC)	0.004747	0.01353	0.005854

This keeps number of signal candidates of
(417201 - 15154) / (449054 - 21957) * 100 = 94 %

D mass plots :
D mass with OffPeak data

Lepton momentum with OffPeak (3D binned)
D momentum with OffPeak (3D binned)
cosBY with OffPeak (3D binned)

Lepton momentum with OffPeak (Bin by bin, D0)
Lepton momentum with OffPeak (Bin by bin, Dch)
D momentum with OffPeak (Bin by bin, D0)
D momentum with OffPeak (Bin by bin, Dch)
cosBY with OffPeak (Bin by bin, D0)
cosBY with OffPeak (Bin by bin, Dch)

Electron only
D mass with OffPeak data

Muon only
D mass with OffPeak data

4. Thrust cut

Tihghter Kaon Selection is applied.
D prob > 0.001 and B prob > 0.01 applied

Using thrust of Dl and non-Dl, apply cuts on |cosTheta_{Dl-nonDl}|

	Sp (D0 + D+)	Err (D0 + D+)
no cut	414308	0.005890
\|cosTheta\| < 0.96	397357	0.005706
0.92	377906	0.005624
0.88	358736	0.005602
0.84	339991	0.005617
0.80	321478	0.005666

Best uncertainty is given by |cosTheta_{Dl-nonDl}| < 0.88
But, since no big difference on uncertainties, we prefer looser cut.
Thus, the best cut is |cosTheta_{Dl-nonDl}| < 0.92

In case of |cosTheta_{Dl-nonDl}| < 0.92 :

	D0	D+	Sum
Dp	707341	1714233	2421574
Ds	351149	1488430	1839579
Sp	237806	140100	377906
Bp	485686	1549233	2034919
Ss	9210	4280	13490
Bs	343352	1430982	1774335
Err	0.004538	0.013015	0.005624
Bp (MC)	459575	1541283	2000859
Bs (MC)	323668	1426667	1750335
Err (MC)	0.004440	0.012989	0.005585

This keeps number of signal candidates of
(375285 - 13260) / (417201 - 15154) * 100 = 90 %

D mass plots :
D mass with OffPeak data

New Plots :

Lepton momentum with OffPeak
D momentum with OffPeak
cosBY with OffPeak
D momentum : Bin by bin D0
D momentum : Bin by bin D+

Plots :

Lepton momentum with OffPeak (3D binned)
D momentum with OffPeak (3D binned)
cosBY with OffPeak (3D binned)

Lepton momentum with OffPeak (Bin by bin, D0)
Lepton momentum with OffPeak (Bin by bin, Dch)
D momentum with OffPeak (Bin by bin, D0)
D momentum with OffPeak (Bin by bin, Dch)
cosBY with OffPeak (Bin by bin, D0)
cosBY with OffPeak (Bin by bin, Dch)

Electron only
D mass with OffPeak data

Muon only
D mass with OffPeak data

5. Bhabha veto

Tihghter Kaon Selection is applied.
D prob > 0.01 and B prob > 0.01 applied
|cosTheta_{Dl-nonDl}| < 0.92 applied

	D0	D+	Sum
Dp	657709	1675082	2332791
Ds	308685	1452006	1760691
Sp	234036	138905	372941
Bp	440150	1513040	1953191
Ss	8795	4167	12963
Bs	302425	1395802	1698227
Err	0.004407	0.012966	0.005582
Bp (MC)	446040	1509871	1955911
Bs (MC)	313360	1396150	1709511
Err (MC)	0.004445	0.012960	0.005591

No significant effect.

D mass plots :
D mass with OffPeak data

Electron only
D mass with OffPeak data

Muon only
D mass with OffPeak data

Cut flow table.
Yeild = sideband subtracted number of candidates.

cuts	OnPeak yeild	efficiency	cumultive efficiency	OffPeak yeild	efficiency	cumultive efficiency
BToDlnu skim	849660	n/a	n/a	241662	n/a	n/a
Tight K	842966	0.9921	0.9921	237307	0.9820	0.9820
Vertexing	727144	0.8626	0.8558	189901	0.8002	0.7858
Thrust cut	583606	0.8026	0.6869	103999	0.5476	0.4303
D0	OnPeak yeild	efficiency	cumultive efficiency	OffPeak yeild	efficiency	cumultive efficiency
BToDlnu skim	506237	n/a	n/a	130926	n/a	n/a
Tight K	499544	0.9868	0.9868	126572	0.9667	0.9667
Vertexing	438337	0.8775	0.8659	102704	0.8114	0.7844
Thrust cut	356192	0.8126	0.7036	56793	0.5530	0.4338
D+	OnPeak yeild	efficiency	cumultive efficiency	OffPeak yeild	efficiency	cumultive efficiency
BToDlnu skim	343423	n/a	n/a	110735	n/a	n/a
Tight K	343422	1.0000	1.0000	110735	1.0000	1.0000
Vertexing	288807	0.8410	0.8410	87197	0.7874	0.7874
Thrust cut	227414	0.7874	0.6622	47206	0.5414	0.4263

cuts	OnPeak - Off Peak yeild	efficiency	cumultive efficiency	BBbar MC yeild	efficiency	cumultive efficiency
BToDlnu skim	607998	n/a	n/a	663692	n/a	n/a
Tight K	605659	0.9961	0.9961	657668	0.9909	0.9909
Vertexing	537243	0.8870	0.8836	589345	0.8961	0.8880
Thrust cut	479607	0.8927	0.7888	524191	0.8894	0.7898
D0	OnPeak - Off Peak yeild	efficiency	cumultive efficiency	BBbar MC yeild	efficiency	cumultive efficiency
BToDlnu skim	375311	n/a	n/a	388905	n/a	n/a
Tight K	372972	0.9938	0.9938	382881	0.9845	0.9845
Vertexing	335633	0.8999	0.8943	351393	0.9178	0.9035
Thrust cut	299399	0.8920	0.7977	314136	0.8940	0.8077
D+	OnPeak - Off Peak yeild	efficiency	cumultive efficiency	BBbar MC yeild	efficiency	cumultive efficiency
BToDlnu skim	232688	n/a	n/a	274787	n/a	n/a
Tight K	232687	1.0000	1.0000	274787	1.0000	1.0000
Vertexing	201610	0.8664	0.8664	237952	0.8660	0.8660
Thrust cut	180208	0.8938	0.7745	210055	0.8828	0.7644