In a data sample of approximately four million hadronic Z decays recorded with the ALEPH detector from 1990 to 1995, a search for the strange b baryon Xi(b) is performed with a study of Xi-lepton correlations. Forty-four events with same sign Xi(-)l(-) combinations are found whereas 8.4 are expected based on the rate of opposite sign Xi(-)l(+) combinations. This significant excess is interpreted as evidence for Xi(b) semileptonic decays. The measured product branching ratio is Br(b-->Xi(b))xBr(Xi(b)-->X(c)Xl(-) (nu)over bar (l))xBr(X(c)-->Xi(-)X')=(5.4 +/- 1.1(stat) +/- 0.8(syst))x10(-4) per lepton species, averaged over electrons and muons, with X(c) a charmed baryon. The Xi(b) lifetime is measured to be tau(Xi b)=1.35 + (-0.28)(+0.37)(stat) + (-0.17)(+0.15)(syst) ps.

D., B., I., D., D., D., P., G., C., G., J. P., L., et al. (1996). Strange b baryon production and lifetime in Z decays. PHYSICS LETTERS. SECTION B, 384, 449-460 [10.1016/0370-2693(96)00925-2].

Strange b baryon production and lifetime in Z decays

CIOCCI, MARIA AGNESE;MARROCCHESI, PIER SIMONE;
1996-01-01

Abstract

In a data sample of approximately four million hadronic Z decays recorded with the ALEPH detector from 1990 to 1995, a search for the strange b baryon Xi(b) is performed with a study of Xi-lepton correlations. Forty-four events with same sign Xi(-)l(-) combinations are found whereas 8.4 are expected based on the rate of opposite sign Xi(-)l(+) combinations. This significant excess is interpreted as evidence for Xi(b) semileptonic decays. The measured product branching ratio is Br(b-->Xi(b))xBr(Xi(b)-->X(c)Xl(-) (nu)over bar (l))xBr(X(c)-->Xi(-)X')=(5.4 +/- 1.1(stat) +/- 0.8(syst))x10(-4) per lepton species, averaged over electrons and muons, with X(c) a charmed baryon. The Xi(b) lifetime is measured to be tau(Xi b)=1.35 + (-0.28)(+0.37)(stat) + (-0.17)(+0.15)(syst) ps.
1996
D., B., I., D., D., D., P., G., C., G., J. P., L., et al. (1996). Strange b baryon production and lifetime in Z decays. PHYSICS LETTERS. SECTION B, 384, 449-460 [10.1016/0370-2693(96)00925-2].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11365/38657
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