Radiative $b$-hadron decays at LHCb

Radiative decays of b -hadrons are ideal to search for New Physics effects. These decays are sen- sitive to the polarization of the emitted photon, which can help to constrain New Physics models in a complementary way to the branching fraction measurements. In this work, I present several results by the LHCb collaboration related to the photon polarization in b → s γ transitions, with special emphasis put on the new time-dependent B 0 s → φ γ analysis. Other analyses discussed are the observation of a non-zero polarization in B + → K + π − π + γ decays, and the angular analysis of B 0 → K ∗ 0 e + e − at the photon pole.