Add to ORKGMeasurement of the B+c meson lifetime using B+c → J/ψµ+νµX decays The LHCb collaboration† The lifetime of the B+c meson is measured using semileptonic decays having a J/ψ meson and a muon in the final state. The data, corresponding to an integrated luminosity of 2 fb−1, are collected by the LHCb detector in pp collisions at a centre-of-mass energy of 8 TeV. The measured lifetime is τ = 509 ± 8 ± 12 fs, where the first uncertainty is statistical and the second is systematic. Submitted to Eur. Phys. J. C c © CERN on behalf of the LHCb collaboration, license CC-BY-3.0. †Authors are listed on the following pages. ar X i