Measuremént of the b baryon lifetime and branching fractions in Z decays

The ALEPH Collaboration

doi:10.1007/s100529800837

Measuremént of the b baryon lifetime and branching fractions in Z decays

The ALEPH Collaboration

Université Paris-Sud
University of São Paulo
INFN Sezione di Bari
INFN Sezione di Catania
Institute of High Energy Physics, Chinese Academy of Sciences
European Organization for Nuclear Research
Université Blaise Pascal
Niels Bohr Institutet
NCSR Demokritos
University of Edinburgh
University of Florence
Florida State University
LNF-INFN
University of Turin
Ev-K2-CNR Committee
University of Glasgow
University of Heidelberg
Imperial College London
University of Innsbruck
Lancaster University
Johannes Gutenberg University
Sezione INFN di Milano
Max-Planck-Institut für Physik
Laboratoire de l'Accélérateur Linéaire
Scuola Normale Superiore di Pisa
Dipartimento di Scienze Biomediche
King's College London
Rutherford Appleton Laboratory
CEA, Irfu, SPP
University of California at Santa Cruz
The University of Sheffield
Universität Siegen
University of Trieste
University of Washington
University of Wisconsin-Madison

Research output: Contribution to journal › Article › peer-review

Abstract

Using approximately 4 million hadronic Ζ decays recorded with the ALEPH detector from 1991 through 1995, the lifetime of the b baryon is measured with three independent methods. From the impact parameter distribution of candidate leptons in 1063 events with Λℓ^- combinations, the average b baryon lifetime is measured to be 1.20 ± 0.08 ± 0.06 ps. From a sample of 193 fully reconstructed Λ⁺ _c candidates correlated with a lepton and a sample of 46 Λℓ⁺ℓ^- combinations, the Λ_b lifetime is measured to be 1.21 ± 0.11 ps. The product branching fractions to these final states are Br(b → Λ_bb) · Br(Λ_b → Λℓ^-v̄X) = 0.326 ± 0.016 ± 0.039% for the first sample and Br(b → Λ_b) · Br(Λ_b → Λ⁺ _cℓ^-v̄X) = 0.86 ± 0.07 ± 0.14% for the second and third samples combined.

Original language	English
Pages (from-to)	197-211
Number of pages	15
Journal	European Physical Journal C
Volume	2
Issue number	2
DOIs	https://doi.org/10.1007/s100529800837
Publication status	Published - 1 Jan 1998

Access to Document

10.1007/s100529800837

Cite this

@article{cdae8f2bc1f146edadf354e059309b61,

title = "Measurem{\'e}nt of the b baryon lifetime and branching fractions in Z decays",

abstract = "Using approximately 4 million hadronic Ζ decays recorded with the ALEPH detector from 1991 through 1995, the lifetime of the b baryon is measured with three independent methods. From the impact parameter distribution of candidate leptons in 1063 events with Λℓ- combinations, the average b baryon lifetime is measured to be 1.20 ± 0.08 ± 0.06 ps. From a sample of 193 fully reconstructed Λ+ c candidates correlated with a lepton and a sample of 46 Λℓ+ℓ- combinations, the Λb lifetime is measured to be 1.21 ± 0.11 ps. The product branching fractions to these final states are Br(b → Λbb) · Br(Λb → Λℓ-{\=v}X) = 0.326 ± 0.016 ± 0.039\% for the first sample and Br(b → Λb) · Br(Λb → Λ+ cℓ-{\=v}X) = 0.86 ± 0.07 ± 0.14\% for the second and third samples combined.",

author = "\{The ALEPH Collaboration\} and R. Barate and D. Buskulic and D. Decamp and P. Ghez and C. Goy and Lees, \{J. P.\} and A. Lucotte and Minard, \{M. N.\} and Nief, \{J. Y.\} and B. Pietrzyk and Casado, \{M. P.\} and M. Chmeissani and P. Comas and Crespo, \{J. M.\} and M. Delfino and E. Fernandez and M. Fernandez-Bosman and Ll Garrido and A. Juste and M. Martinez and G. Merino and R. Miquel and Mir, \{Ll M.\} and C. Padilla and Park, \{I. C.\} and A. Pascual and Perlas, \{J. A.\} and I. Riu and F. Sanchez and A. Colaleo and D. Creanza and \{de Palma\}, M. and G. Gelao and G. Iaselli and G. Maggi and M. Maggi and N. Marinelli and S. Nuzzo and A. Ranieri and G. Raso and F. Ruggieri and G. Selvaggi and L. Silvestris and P. Tempesta and A. Tricomi and G. Zito and X. Huang and J. Lin and Q. Ouyang and M. Verderi",

year = "1998",

month = jan,

day = "1",

doi = "10.1007/s100529800837",

language = "English",

volume = "2",

pages = "197--211",

journal = "European Physical Journal C",

issn = "1434-6044",

number = "2",

}

TY - JOUR

T1 - Measuremént of the b baryon lifetime and branching fractions in Z decays

AU - The ALEPH Collaboration

AU - Barate, R.

AU - Buskulic, D.

AU - Decamp, D.

AU - Ghez, P.

AU - Goy, C.

AU - Lees, J. P.

AU - Lucotte, A.

AU - Minard, M. N.

AU - Nief, J. Y.

AU - Pietrzyk, B.

AU - Casado, M. P.

AU - Chmeissani, M.

AU - Comas, P.

AU - Crespo, J. M.

AU - Delfino, M.

AU - Fernandez, E.

AU - Fernandez-Bosman, M.

AU - Garrido, Ll

AU - Juste, A.

AU - Martinez, M.

AU - Merino, G.

AU - Miquel, R.

AU - Mir, Ll M.

AU - Padilla, C.

AU - Park, I. C.

AU - Pascual, A.

AU - Perlas, J. A.

AU - Riu, I.

AU - Sanchez, F.

AU - Colaleo, A.

AU - Creanza, D.

AU - de Palma, M.

AU - Gelao, G.

AU - Iaselli, G.

AU - Maggi, G.

AU - Maggi, M.

AU - Marinelli, N.

AU - Nuzzo, S.

AU - Ranieri, A.

AU - Raso, G.

AU - Ruggieri, F.

AU - Selvaggi, G.

AU - Silvestris, L.

AU - Tempesta, P.

AU - Tricomi, A.

AU - Zito, G.

AU - Huang, X.

AU - Lin, J.

AU - Ouyang, Q.

AU - Verderi, M.

PY - 1998/1/1

Y1 - 1998/1/1

N2 - Using approximately 4 million hadronic Ζ decays recorded with the ALEPH detector from 1991 through 1995, the lifetime of the b baryon is measured with three independent methods. From the impact parameter distribution of candidate leptons in 1063 events with Λℓ- combinations, the average b baryon lifetime is measured to be 1.20 ± 0.08 ± 0.06 ps. From a sample of 193 fully reconstructed Λ+ c candidates correlated with a lepton and a sample of 46 Λℓ+ℓ- combinations, the Λb lifetime is measured to be 1.21 ± 0.11 ps. The product branching fractions to these final states are Br(b → Λbb) · Br(Λb → Λℓ-v̄X) = 0.326 ± 0.016 ± 0.039% for the first sample and Br(b → Λb) · Br(Λb → Λ+ cℓ-v̄X) = 0.86 ± 0.07 ± 0.14% for the second and third samples combined.

AB - Using approximately 4 million hadronic Ζ decays recorded with the ALEPH detector from 1991 through 1995, the lifetime of the b baryon is measured with three independent methods. From the impact parameter distribution of candidate leptons in 1063 events with Λℓ- combinations, the average b baryon lifetime is measured to be 1.20 ± 0.08 ± 0.06 ps. From a sample of 193 fully reconstructed Λ+ c candidates correlated with a lepton and a sample of 46 Λℓ+ℓ- combinations, the Λb lifetime is measured to be 1.21 ± 0.11 ps. The product branching fractions to these final states are Br(b → Λbb) · Br(Λb → Λℓ-v̄X) = 0.326 ± 0.016 ± 0.039% for the first sample and Br(b → Λb) · Br(Λb → Λ+ cℓ-v̄X) = 0.86 ± 0.07 ± 0.14% for the second and third samples combined.

U2 - 10.1007/s100529800837

DO - 10.1007/s100529800837

M3 - Article

AN - SCOPUS:0032437788

SN - 1434-6044

VL - 2

SP - 197

EP - 211

JO - European Physical Journal C

JF - European Physical Journal C

IS - 2

ER -

Measuremént of the b baryon lifetime and branching fractions in Z decays

Abstract

Access to Document

Fingerprint

Cite this