b-flavour tagging in pp collisions at LHCb

Measurements of CP violation and flavour oscillations of neutral B mesons require the knowledge of the meson flavour at the production time. Flavour-tagging algorithms in the LHCb experiment allow to perform such measurements with very high precision. Recent examples include the determination of the CKM angles 2 beta and 2 beta(s). The details of these flavour-tagging algorithms are presented, together with their performances.