A Precise measurement of the $B^{+}$, $B^0$ and mean $b$ hadron lifetime with the DELPHI detector at LEP1

Final results from the DELPHI Collaboration on the lifetime of B+ and B0 mesons and the mean b-hadron lifetime, are presented using the data collected at the Z0 peak in 1994 and 1995. Elaborate, inclusive, secondary vertexing methods have been employed to ensure a b-hadron reconstruction with good efficiency. To separate samples of B+ and B0 mesons, high performance neural network techniques are used that achieve very high purity signals. The results obtained are: tau_B+ = 1.624 +/- 0.014 (stat) +/- 0.018 (syst) ps tau_B0 = 1.531 +/- 0.021 (stat) +/- 0.031 (syst) ps tau_B+/tau_B0 = 1.060 +/- 0.021 (stat) +/- 0.024 (syst) and for the average b-hadron lifetime: tau_b = 1.570 +/- 0.005 (stat) +/- 0.008 (syst) ps.

Note:

30 pages, 10 figures, Accepted by Eur. Phys. J. C Report-no: CERN-EP/2003-065

electron positron: colliding beams
electron positron: annihilation
Z0: electroproduction
Z0: hadronic decay
bottom: pair production
B: decay modes
bottom particle: lifetime
B0: lifetime
B+: lifetime
lifetime: ratio

References(29)

Figures(0)

The CKM Matrix and the Unitarity Triangle. Proceedings, Workshop13-16 Feb 2002 CERN, Geneva, Switzerland,

et al.

e-Print:
- hep-ph/0304132
•
DOI:
- 10.5170/CERN-2003-002-corr

Review of particle physics. Particle Data Group

et al.

- Phys.Rev.D 66 (2002) 010001
•
DOI:
- 10.1103/PhysRevD.66.010001

BSAURUS: A Package for inclusive B reconstruction in DELPHI

et al.

e-Print:
- hep-ex/0102001

The DELPHI detector at LEP

DELPHI

Collaboration

•

P.A. Aarnio

et al.

- Nucl.Instrum.Meth.A 303 (1991) 233-276
•
DOI:
- 10.1016/0168-9002(91)90793-P

Performance of the DELPHI detector

DELPHI

Collaboration

•

P. Abreu

et al.

- Nucl.Instrum.Meth.A 378 (1996) 57-100
•
DOI:
- 10.1016/0168-9002(96)00463-9

The DELPHI silicon strip microvertex detector with double sided readout

DELPHI

Collaboration

•

V. Chabaud
(
- CERN
)

et al.

- Nucl.Instrum.Meth.A 368 (1996) 314-332
•
DOI:
- 10.1016/0168-9002(95)00699-0

High-energy physics event generation with PYTHIA 5.7 and JETSET 7.4

Torbjorn Sjostrand
(
- CERN
)

- Comput.Phys.Commun. 82 (1994) 74-90,
- CERN Geneva - TH. 7111 (93/12,rec.Jan.94) 17 p. and e: CERN th-7111-93
•
DOI:
- 10.1016/0010-4655(94)90132-5

Tuning and test of fragmentation models based on identified particles and precision event shape data

DELPHI

Collaboration

•

P. Abreu

et al.

- Z.Phys.C 73 (1996) 11-60
•
DOI:
- 10.1007/s002880050295

Inclusive Sigma- and Lambda(1520) production in hadronic Z decays

DELPHI

Collaboration

•

P. Abreu

et al.

- Phys.Lett.B 475 (2000) 429-447
•
e-Print:
- hep-ex/0103020
•
DOI:
- 10.1016/S0370-2693(00)00081-2

MACRIB: High efficiency high purity hadron identification for DELPHI

DELPHI

Collaboration

•

Zoltan Albrecht
(
- Karlsruhe U., EKP
)

et al.

e-Print:
- hep-ex/0111081

Measurement of the inclusive decay properties of charmed mesons

MARK-III

Collaboration

•

D. Coffman
(
- Caltech
)

et al.

- Phys.Lett.B 263 (1991) 135-140
•
DOI:
- 10.1016/0370-2693(91)91718-B

A Measurement of $B^{+}$ and $B^0$ lifetimes using $\bar{D} \ell^+$ events

DELPHI

Collaboration

•

P. Abreu

et al.

- Z.Phys.C 68 (1995) 13-24

A Precise measurement of the B(d)0 meson lifetime using a new technique

DELPHI

Collaboration

•

P. Abreu

et al.

- Z.Phys.C 74 (1997) 19-32,
- Z.Phys.C 75 (1997) 579 (erratum)
•
DOI:
- 10.1007/s002880050367

Lifetimes of charged and neutral B hadrons using event topology

DELPHI

Collaboration

•

W. Adam

et al.

- Z.Phys.C 68 (1995) 363-374,
- Z. Phys. C68 (1995) 363-374, and CERN Geneva - CERN-PPE-95-059 (95/04,rec.May) 22 p. e: CERN ppe95-059
•
DOI:
- 10.1007/BF01620712