Study Majorana neutrino contribution to B-meson semi-leptonic rare decays

B  -meson semi-leptonic rare decays are sensitive to new physics beyond standard model. We study the B−→π−μ+μ−B−→π−μ+μ− process and investigate the Majorana neutrino contribution besides the standard model contribution to its decay width. The standard model predictions are estimated with Heavy Quark Symmetry and Lattice QCD, perturbative QCD and QCD Light Cone Sum Rule. The constraints on the Majorana neutrino mass and mixing parameter are obtained from this decay channel with the latest LHCb data. Utilizing the best fits for the parameters, we study the lepton number violating decay B−→π+μ−μ−B−→π+μ−μ−, and find its branching ratio is roughly consistent with the LHCb data reported recently.