July 31, 2017 to August 4, 2017
Fermi National Accelerator Laboratory
US/Central timezone

A novel, precise measurement of $B^0_s$ and $D^-_s$ lifetimes at LHCb

Aug 1, 2017, 2:24 PM
Racetrack (Fermi National Accelerator Laboratory)


Fermi National Accelerator Laboratory

Presentation Quark and Lepton Flavor Quark and Lepton Flavor


Mr Diego Tonelli (INFN Trieste)


The LHCb collabotration reports on a new measurement of the flavor-specific $B^0_s$ lifetime and of the $D^0_s$ lifetime based on semileptonic decays. Using proton-proton collisions at center-of-mass energies of 7 and 8 TeV, and corresponding to 3.0 fb$^{-1}$ of integrated luminosity, $B^0_s \rightarrow D^{(*)-}_s \mu^+ \nu_\mu$ decays are partially reconstructed in the $K^+K^-\pi^-\mu^+$ final state. Based on a novel approach, the lifetimes are determined from the variation in the $B^0_s$ signal yield as a function of decay time, relative to that of $B^0$ decays that are reconstructed in the same finel state, and whose lifetime is precisely known. The use of kinematically similar $B^0$ decays as a reference allows the reduction of the uncertainties from partial reconstruction and lifetime-biasing selection criteria. The results greatly improve over the current determinations. Our approach circumvents the systematic limitations typically associated with lifetime measurements using semileptonic decays in hadron collisions and paves the way toward a fruitful program of similar measurements.

Primary author

Dr Marco Gersabeck (The University of Manchester)

Presentation materials