A measurement of the $\mathrm{B}_s^0$ lifetime using reconstructed $\mathrm{D}_s^-$ mesons

The OPAL Collaboration:     K. Ackerstaff - et al.

doi:doi:10.1007/s100529800839

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2018 Impact factor 4.843

Particles and Fields

Eur. Phys. J. C 2, 407-416
DOI 10.1007/s100529800839

A measurement of the $\bf \mathrm{B_s^0}$ lifetime using reconstructed $\bf \mathrm{ D_s^-}$ mesons

The OPAL Collaboration, K.Ackerstaff⁸ et al.

⁸ CERN, European Organisation for Particle Physics, CH-1211 Geneva 23, Switzerland

Received: 25 July 1997 / Published online: 10 March 1998

Abstract
We report a measurement of the $\mathrm{B_s^0}$ meson lifetime from $\mathrm{B_s^0}\to \mathrm{ D_s^-}\rm{X}$ decays, where $\mathrm{ D_s^-}$ mesons are reconstructed in the $\mathrm{ D_s^-}\to \mathrm{\phi\pi^-}$ and $\mathrm{ D_s^-}\to\mathrm{K^{*0}K^-}$ decay channels. From approximately 3.7 million hadronic $\mathrm{Z}^0$ decays recorded by the OPAL detector at LEP a sample is selected containing 911 $\pm$ 83 candidates, of which $519 \pm 136$ are estimated to be from $\mathrm{B_s^0}$ meson decays. Fitting the distribution of the distance from the beam spot to the decay vertex of the $\mathrm{ D_s^-}$ candidates with an unbinned likelihood function we measure