Measurement of the $B_c^{+}$ meson lifetime using $B_c^{+}\to J/\ddot{I}ˆ\hat{I}{¼}^{+}\hat{I}{½}_{\hat{I}}¼X$ decays

Abstract

The lifetime of the $B_c^{+}$ meson is measured using semileptonic decays having a $J/\ddot{I}ˆ$ meson and a muon in the final state. The data, corresponding to an integrated luminosity of $2\mathrm{f}{\mathrm{b}}^{-1}$, are collected by the LHCb detector in $pp$ collisions at a centre-of-mass energy of $8\mathrm{TeV}$. The measured lifetime is $$\ddot{I}„=509\pm 8\pm 12\mathrm{fs},$$ where the first uncertainty is statistical and the second is systematic.