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Study of the B(s)0 anti-B(s)0 oscillation frequency using D(s)- lepton+ combinations in Z decays

The ALEPH collaboration Buskulic, D. ; De Bonis, I. ; Decamp, D. ; et al.
Phys.Lett.B 377 (1996) 205-221, 1996.
Inspire Record 417261 DOI 10.17182/hepdata.52362

A lower limit on the oscillation frequency of the B s 0 B s 0 system is obtained from approximately four million hadronic Z decays accumulated using the ALEPH detector at LEP from 1991 to 1995. Leptons are combined with opposite sign D s − candidates reconstructed in seven different decay modes as evidence of semileptonic B s 0 decays. Criteria designed to ensure precise proper time reconstruction select 277D s − ℓ + combinations. The initial state of these B s 0 candidates is determined using an algorithm optimized to efficiently utilise the tagging information available for each event. The limit at 95% confidence level on the B s 0 B s 0 oscillation frequency is Δm s > 6.6 ps −1 . The same data is used to update the measurement of the B s 0 lifetime, τ s = 1.54 −0.13 +0.14 (stat) ± 0.04 (syst) ps.

2 data tables
Table 1

This result supersedes the previous measurement ( 1.59 +0.17 -0.15 (stat.) +-0.03 (sys.) ps ) presented in reference PL 361B, 221.

Table 2

No description provided.


A Precise measurement of the average b hadron lifetime

The ALEPH collaboration Buskulic, D. ; Casper, D. ; De Bonis, I. ; et al.
Phys.Lett.B 369 (1996) 151-162, 1996.
Inspire Record 401554 DOI 10.17182/hepdata.52363

An improved measurement of the average b hadron lifetime is performed using a sample of 1.5 million hadronic Z decays, collected during the 1991–1993 runs of ALEPH, with the silicon vertex detector fully operational. This uses the three-dimensional impact parameter distribution of lepton tracks coming from semileptonic b decays and yields an average b hadron lifetime of 1.533 ± 0.013 ± 0.022 ps.

1 data table
Table 1

No description provided.


Production of strange B baryons decaying into Xi-+ - lepton-+ pairs at LEP

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Z.Phys.C 68 (1995) 541-554, 1995.
Inspire Record 393792 DOI 10.17182/hepdata.52371

None

2 data tables
Table 1

HERE 'PRODUCTION FRACTION' IS PROBABILITY(BQ --> B-BARYON)*BR(B-BARYON --> XI- LEPTON- X). 'LEPTON' IS E OR MU.

Table 2

No description provided.


New experimental limits for the electron stability

Aharonov, Y. ; Avignone, F.T. ; Brodzinski, R.L. ; et al.
Phys.Lett.B 353 (1995) 168-172, 1995.
Inspire Record 405543 DOI 10.17182/hepdata.47856

A set of two natural abundance Ge detectors of 1.1 kg each, located in the Homestake mine, and one small, 0.253 kg, Ge detector operating in the Canfranc railway tunnel in Spain, have been used to obtain bounds on the stability of the electron against the decay modes e − → γν e and e − → ν e ν e ν e . The bounds on the mean lifes are τ ( γν e ) > 3.7(2.1) × 10 25 yr , 68%(90%) CL and τ(ν e ν e ν e > 4.3(2.6) × 10 23 yr , 68%(90%) CL, which are at present the most stringent laboratory limits for these decays.

1 data table
Table 1

Lifetime in years (YR).