Evidence for the decay B⁺c → J/ψ3π⁺2π^-

Evidence is presented for the decay B ⁺ _c → J/ψ3π ⁺2π ^- using proton-proton collision data, corresponding to an integrated luminosity of 3 fb ⁻¹, collected with the LHCb detector. A signal yield of 32 ± 8 decays is found with a significance of 4.5 standard deviations. The ratio of the branching fraction of the B ⁺ _c → J/ψ3π ⁺2π ^- decay to that of the B ⁺ _c → J/ψ3π ⁺ decay is measured to be (Formula Presented) where the first uncertainty is statistical and the second is systematic.