New algorithms for identifying the flavour of ${\mathrm {B}} ^0$ mesons using pions and protons

Two new algorithms for use in the analysis of $pp$ collision are developed to identify the flavour of ${\mathrm {B}} ^0$ mesons at production using pions and protons from the hadronization process. The algorithms are optimized and calibrated on data, using ${{\mathrm {B}} ^0} \!\rightarrow D^{-}\pi ^{+}$ decays from $pp$ collision data collected by LHCb at centre-of-mass energies of 7 and 8 TeV . The tagging power of the new pion algorithm is 60% greater than the previously available one, the algorithm using protons to identify the flavour of a ${\mathrm {B}} ^0$ meson is the first of its kind.