Garra Ticó, JordiGraugés Pous, EugeniBABAR Collaboration2019-04-052019-04-052008-07-151550-7998https://hdl.handle.net/2445/131519Using 230 × 10 6 B ¯¯¯ B events recorded with the BABAR detector at the e + e − storage rings PEP-II, we reconstruct approximately 4100 B 0 → J / ψ K + π − and 9930 B + → J / ψ K + decays with J / ψ → μ + μ − and e + e − . From the measured B -momentum distributions in the e + e − rest frame, we determine the mass difference m ( B 0 ) − m ( B + ) = ( + 0.33 ± 0.05 ± 0.03 )     MeV / c 2 .8 p.application/pdfeng(c) American Physical Society, 2008Física de partículesExperimentsParticle physicsExperimentsinfo:eu-repo/semantics/article5776802019-04-05info:eu-repo/semantics/openAccess