Measurement of the B/s0 Lifetime and Study of B/s0 anti-B/s0 Oscillations using D/s l Events

TL;DR

This study measures the B_s0 meson lifetime and sets limits on its oscillation parameters using data from Z0 decays, providing key insights into B_s0 properties and mixing phenomena.

Contribution

The paper presents the first measurement of B_s0 lifetime and limits on its oscillation frequency using DELPHI data from 1992-1995.

Findings

B_s0 lifetime measured as approximately 1.42 ps

Upper limit on width difference ratio: < 0.46 at 95% C.L.

Lower limit on mass difference: > 7.4 ps^{-1} at 95% C.L.

Abstract

Lifetime and oscillations of B0s mesons have been studied in events with a large transverse momentum lepton and a Ds of opposite electric charge in the same hemisphere, selected from about 3.6 million hadronic Z0 decays accumulated by DELPHI between 1992 and 1995. The B0s lifetime and the fractional width difference between the two physical B0s states have been found to be: \tau_(B0s) = (1.42^{+0.14}_{-0.13}(stat.) +/- 0.03(syst.)) ps \Delta\Gamma(B0s)/\Gamma(B0s) < 0.46 at the 95% C.L. In the latter result it has been assumed that \tau_(B0s)=\tau_(B0d). Using the same sample, a limit on the mass difference between the physical B0s states has been set: Delta(m_B0s) > 7.4 ps^{-1} at the 95% C.L. with a corresponding sensitivity equal to 8.1 ps^{-1}.