Measurement of R(J/ψ): the ratio of branching fractions between Bc+→J/ψτ+ντ and Bc+→J/ψμ+νμ using τ+→ μ+νμ ντ decays. [R(J/ψ) = 0.71±0.17±0.18] Today, at the open session of the Large Hadron Collider Committee, LHCC, the LHCb collaboration presented the result of a new measurement of the ratio of branching fractions, R(J/ψ), between Bc+→J/ψτ+ντ and Bc+→J/ψμ+νμ using τ+→…