Journal of High Energy Physics, cilt.2014, sa.10, ss.1-18, 2014 (SCI-Expanded)
First observations of the rare decays B+→ K+π+π-μ+μ-and B+→ φK+μ+μ-are presented using data corresponding to an integrated luminosity of 3.0 fb-1, collected by the LHCb experiment at centre-of-mass energies of 7 and 8TeV. The branching fractions of the decays are (Formula Presented.) where the uncertainties are statistical, systematic, and due to the uncertainty on the branching fractions of the normalisation modes. A measurement of the differential branching fraction in bins of the invariant mass squared of the dimuon system is also presented for the decay B+→ K+π+π-μ+μ-.