Rare Decays at LHCb

Rare loop-induced decays are sensitive to New Physics in many Standard Model extensions. In this paper we discuss the reconstruction of the radiative penguin decays $B^0_d \to K^{*0} \gamma, B^0_s \to \phi \gamma , B^0_d \to \omega \gamma, \Lambda_b \to \Lambda \gamma$, the electroweak penguin decays $B^0_d \to K^{*0} \mu^+ \mu^-, B^+_u \to K^+ \mu^+ \mu^-$, the gluonic penguin decays $B^0_d \to \phi K^0_S, B^0_s \to \phi \phi$, and the decay $B^0_s \to \mu^+\mu^-$ at LHCb. The selection criteria, evaluated efficiencies, expected annual yields and $B/S$ estimates are presented.