Performance of b-tagging algorithms at the CMS experiment with pp collision data at $\sqrt s$=8 TeV

The identification of jets originating from b quarks is crucial both for the searches for new physics and for the measurement of standard model processes. The Compact Muon Solenoid (CMS) collaboration at the Large Hadron Collider (LHC) has developed a variety of algorithms to select b-quark jets based on variables such as the impact parameter of charged particle tracks, properties of reconstructed secondary vertices from heavy hadron decays, and the presence or absence of a lepton in the jet, or combinations thereof. Performance measurements of these b-jet identification algorithms are presented, using multijet and $t\overline{t}$ events recorded in proton-proton collision data at $\sqrt s$=8 TeV with the CMS detector during the LHC Run 1.