Measurement of $B^0, B^0_s, B^+$ and $\Lambda_{b}^{0}$production asymmetries in 7 and 8TeV $pp$ collisions at LHCb

The $B^0, B_{s}^{0},B^+ and \Lambda_{b}^{0}$ hadron production asymmetries are mea-sured using a data sample corresponding to an integrated luminosity of 3.0 fb$^−1$,collected by the LHCb experiment in proton-proton collisions at centre-of-mass en-ergies of 7 and 8 TeV. The measurements are performed as a function of transversemomentum and rapidity of thebhadrons within the LHCb detector acceptance. Theoverall production asymmetries, integrated over transverse momentum and rapidity,are also determined.