Searches for Majorana neutrinos in $B^-$ decays

Searches for heavy Majorana neutrinos in B- decays in final states containing hadrons plus a \mu- \mu- pair have been performed using 0.41/fb of data collected with the LHCb detector in proton-proton collisions at a center-of-mass energy of 7 TeV. The D+ \mu- \mu- and D*+ \mu- \mu- final states can arise from the presence of virtual Majorana neutrinos of any mass. Other final states containing \pi+, Ds+, or D0\pi+ can be mediated by an on-shell Majorana neutrino. No signals are found and upper limits are set on Majorana neutrino production as a function of mass, and also on the B- decay branching fractions.