Lattice calculation of BSM B-parameters using improved staggered fermions in N_f=2+1 unquenched QCD

Indirect CP violation in the neutral kaon system is parameterized by epsilon_K. In the standard model (SM), the epsilon_K can be expressed in terms of B_K, which is a non-perturbative parameter that describes the mixing between neutral kaons, and which can be determined using the lattice QCD simulations. However, recent results of B_K indicate that there is a substantial gap of 3-sigma between the SM prediction and the experimental value of epsilon_K in the exclusive V_cb channel. Hence beyond the SM (BSM) physics draw more attention, now. There are, in general, four additional four-fermion operators which can come from the BSM physics such as supersymmetry, technicolors, extra dimensions, etc. Their contributions to epsilon_K can be parameterized by the BSM B-parameters, which are also non-perturbative parameters that describe the mixing of neutral kaons through BSM heavy particles. In this talk, I present the lattice calculation of the BSM B-parameters in N_f = 2+1 unquenched QCD simulations using improved staggered fermions.