Preliminary DØ B-Physics Results at Lepton-Photon 2003

updated: 7-Aug-03

Reconstructed Decays

Decay Lumi
[pb-1] Signal Comments

J/psi --> mu+ mu- 114 290296
M = 3072+-74 MeV
PDG = 3097 MeV

psi' --> mu+ mu- 114 8222
M = 3668+-71 MeV
PDG = 3686 MeV

B+- --> J/psi K+- 114 1235+-52 HTFAA-ext

Bd --> J/psi Ks 114 157+-20 HTFAA-ext

Bd --> J/psi K*0
    K* --> K+ pi- 114 509+-37 HTFAA-ext

Bs --> J/psi phi
    phi --> K+ K- 114 113+-17 HTFAA-ext

B --> D+- mu X
    D+ --> K- pi+ pi+ 6.2 1067+-66 HTFAA-ext

B --> D+ mu X
    D+ --> phi pi+ 6.2 72+-29 HTFAA-ext

Bd --> D* mu X
    D* --> D0 pi
    D0 --> K- pi+ 6.2 1132+-50 HTFAA-ext

B --> D0 mu X
    D0 --> K- pi+ 6.2 2537+-88 HTFAA-ext

Bs --> Ds mu X
    Ds --> phi pi+ 6.2 279+-32 HTFAA-ext

B**d --> B+ pi-
    B+ --> J/psi K+ 114 65+-17
M = 5710+-16 MeV B** Analysis
PDG = 5698+-8 GeV

B**+ --> Bd pi+
    Bd --> J/psi K* 114 not signif. B** Analysis

chi_c1 --> J/psi gamma
chi_c2 --> J/psi gamma
    gamma --> e+ e- 114 77+-11
33+-9

Lifetimes

All results for L = 114 pb-1, except B --> D0 mu X.
* = modified from documentation posted on web

Decay Signal (fraction) Lifetime [ps]
(ctau [um]) PDG [ps] Main Systematics

B --> J/psi X ??? (0.18) 1.562+-0.013+-0.044
(468+-4+-13)* 1.564+-0.014

Decay Length Bias (9um)

P Scale Factor (8um)

Alignment (5um)

B+- --> J/psi K+- 652 (0.15) 1.65+-0.08+0.13
(495+-25+31-37)* 1.674+-0.018

Mass Window (28um)

Signal Fraction (22um)

Bd --> J/psi K* 105+-19 (0.11) 1.51+0.19-0.17+-0.20
(453+58-51+-60) 1.542+-0.016

MC check of Fit (56um)

Pt(B) (20um)

Bs --> J/psi phi 69+-13 (0.22) 1.19+0.19-0.16+-0.14
(357+58-42+-41) 1.461+-0.057

MC check of Fit (35um)

Pt(B) (20um)

tau(Bs)/tau(Bd) 0.79+-0.14

/\b --> J/psi /\ 56+-14 (0.16) 1.05+0.21-0.18+-0.12
(315+64-55+-36) 1.229+-0.080

Split Sample in Phi (22um)

MC check of Fit (15um)

B --> D0 mu X
(L = 12 pb-1) 1276 (0.16) 1.460+-0.083(stat)
(438+-25) 1.60+-0.02

Reconstruction (<60um)

MC check of Fit (<60um)

Flavor Tagging

All results for L = 114 pb-1
Flavor reconstruction from B+- --> J/psi K+-

Soft Muon Jet Charge

N events 1964 1017

N correct tag 63 301

N wrong tag 37 174

N signal 52.5 475 ?

N bgrd 47.5 0 ?

Signal Efficiency (%) 5.0+-0.7 46.7+-1.56

Signal Dilution (%) 57.0+-19.3 26.7+-4.53

Signal Eff * D² (%) 1.6+-0.6 3.3+-0.8

Run II B WG Eff * D² (%) 1.7 3.0

Flavor Changing Neutral Currents

All results for L = 114 pb-1

Decay Candidates Background Limit [90 % CL] Previous

Bs --> mu+ mu- 3 3.42+-0.79 1.6 e-6 2.0 e-6 (CDF Run I)

Decay	Lumi [pb-1]	Signal	Comments
J/psi --> mu+ mu-	114	290296 M = 3072+-74 MeV	PDG = 3097 MeV
psi' --> mu+ mu-	114	8222 M = 3668+-71 MeV	PDG = 3686 MeV
B+- --> J/psi K+-	114	1235+-52	HTFAA-ext
Bd --> J/psi Ks	114	157+-20	HTFAA-ext
Bd --> J/psi K0 K --> K+ pi-	114	509+-37	HTFAA-ext
Bs --> J/psi phi phi --> K+ K-	114	113+-17	HTFAA-ext
B --> D+- mu X D+ --> K- pi+ pi+	6.2	1067+-66	HTFAA-ext
B --> D+ mu X D+ --> phi pi+	6.2	72+-29	HTFAA-ext
Bd --> D* mu X D* --> D0 pi D0 --> K- pi+	6.2	1132+-50	HTFAA-ext
B --> D0 mu X D0 --> K- pi+	6.2	2537+-88	HTFAA-ext
Bs --> Ds mu X Ds --> phi pi+	6.2	279+-32	HTFAA-ext
B**d --> B+ pi- B+ --> J/psi K+	114	65+-17 M = 5710+-16 MeV	B** Analysis PDG = 5698+-8 GeV
B*+ --> Bd pi+ Bd --> J/psi K	114	not signif.	B** Analysis
chi_c1 --> J/psi gamma chi_c2 --> J/psi gamma gamma --> e+ e-	114	77+-11 33+-9

Decay	Signal (fraction)	Lifetime [ps] (ctau [um])	PDG [ps]	Main Systematics
B --> J/psi X	??? (0.18)	1.562+-0.013+-0.044 (468+-4+-13)*	1.564+-0.014	Decay Length Bias (9um) P Scale Factor (8um) Alignment (5um)
B+- --> J/psi K+-	652 (0.15)	1.65+-0.08+0.13 (495+-25+31-37)*	1.674+-0.018	Mass Window (28um) Signal Fraction (22um)
Bd --> J/psi K*	105+-19 (0.11)	1.51+0.19-0.17+-0.20 (453+58-51+-60)	1.542+-0.016	MC check of Fit (56um) Pt(B) (20um)
Bs --> J/psi phi	69+-13 (0.22)	1.19+0.19-0.16+-0.14 (357+58-42+-41)	1.461+-0.057	MC check of Fit (35um) Pt(B) (20um)
tau(Bs)/tau(Bd)		0.79+-0.14
/\b --> J/psi /\	56+-14 (0.16)	1.05+0.21-0.18+-0.12 (315+64-55+-36)	1.229+-0.080	Split Sample in Phi (22um) MC check of Fit (15um)
B --> D0 mu X (L = 12 pb-1)	1276 (0.16)	1.460+-0.083(stat) (438+-25)	1.60+-0.02	Reconstruction (<60um) MC check of Fit (<60um)

	Soft Muon	Jet Charge
N events	1964	1017
N correct tag	63	301
N wrong tag	37	174
N signal	52.5	475 ?
N bgrd	47.5	0 ?
Signal Efficiency (%)	5.0+-0.7	46.7+-1.56
Signal Dilution (%)	57.0+-19.3	26.7+-4.53
*Signal Eff D² (%)**	1.6+-0.6	3.3+-0.8
*Run II B WG Eff D² (%)**	1.7	3.0

Decay	Candidates	Background	Limit [90 % CL]	Previous
Bs --> mu+ mu-	3	3.42+-0.79	1.6 e-6	2.0 e-6 (CDF Run I)