# Measurement of the $B_s^0$ lifetime in the flavor-specific decay channel $B_s^0 \to D_s^- \mu^+\nu X$

Abstract : We present an updated measurement of the $B_s^0$ lifetime from the D0 collaboration using the semileptonic decays $B_s^0\rightarrow D_s^-\mu^+\nu X$, with $D_s^- \to \phi \pi^-$ and $\phi \to K^+K^-$ (and the charge conjugate process). This measurement uses the full Tevatron Run II sample of proton-antiproton collisions at $\sqrt{s} = 1.96$~TeV, comprising an integrated luminosity of 10.4~fb$^{-1}$. We find a flavor-specific lifetime $\tau_{\mathrm{fs}}(B_s^0)=1.479\pm0.010\thinspace{\rm(stat)}\pm0.021\thinspace{\rm(syst)}\thinspace\rm{ps}$. This technique is also used to determine the $B^0$ lifetime using the analogous $B^0\to D^-\mu^+\nu X$ decay with $D^-\to\phi\pi^-$, yielding $\tau(B^0)=1.534\pm0.019\thinspace{\rm(stat)}\pm0.021\thinspace{\rm(syst)}\thinspace\rm{ps}$. Both measurements are consistent with the current world averages, and the $B_s^0$ lifetime measurement is the most precise to date. Taking advantage of the cancellation of systematic uncertainties, we determine the lifetime ratio $\tau_{\mathrm{fs}}(B_s^0)/\tau(B^0) = 0.964\pm0.013\thinspace{\rm(stat)}\pm0.007\thinspace{\rm(syst)}$.
Document type :
Journal articles

http://hal.in2p3.fr/in2p3-01072258
Contributor : Danielle Cristofol <>
Submitted on : Wednesday, October 8, 2014 - 8:15:10 AM
Last modification on : Wednesday, September 16, 2020 - 4:27:50 PM

### Citation

V.M. Abazov, M.-C. Cousinou, A. Duperrin, W. Geng, E. Kajfasz, et al.. Measurement of the $B_s^0$ lifetime in the flavor-specific decay channel $B_s^0 \to D_s^- \mu^+\nu X$. Physical Review Letters, American Physical Society, 2015, 114, pp.062001. ⟨10.1103/PhysRevLett.114.062001⟩. ⟨in2p3-01072258⟩

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