Measurement of the lifetime of the Bc+ meson using the Bc+→ J/ψπ+ decay mode

Abstract

The difference in total widths between the Bc+ and B+mesons is measured using a data sample corresponding to an integrated luminosity of 3.0 fb-1collected by the LHCb experiment in 7 and 8 TeV centre-of-mass energy proton-proton collisions at the LHC. Through the study of the time evolution of Bc+→J/ψπ+ and B+→J/ψK+decays, the width difference is measured to beδΓ≡ΓBc+-ΓB+=4.46±0.14±0.07mm-1c, where the first uncertainty is statistical and the second systematic. The known lifetime of the B+meson is used to convert this to a precise measurement of the Bc+ lifetime,τBc+=513.4±11.0±5.7fs, where the first uncertainty is statistical and the second is systematic.