Measurement of the ¯¯¯ B 0 s Effective Lifetime in the J / ψ f 0 ( 980 ) Final State

Abstract

The effective lifetime of the ¯¯¯ B 0 s meson in the decay mode ¯¯¯ B 0 s → J / ψ f 0 ( 980 ) is measured using 1.0

fb − 1 of data collected in p p collisions at √ s = 7

TeV with the LHCb detector. The result is 1.700 ± 0.040 ± 0.026

ps , where the first uncertainty is statistical and the second systematic. As the final state is C P -odd, and C P violation in this mode is measured to be small, the lifetime measurement can be translated into a measurement of the decay width of the heavy ¯¯¯ B 0 s mass eigenstate, Γ H = 0.588 ± 0.014 ± 0.009

ps − 1 .