B^0-\bar{B}^0 mixing with quenched lattice NRQCD

TL;DR

This paper reports on lattice QCD calculations of B-parameters relevant for B-meson mixing, using quenched NRQCD and improved light quark actions, providing results with systematic uncertainty analysis.

Contribution

It presents new quenched lattice QCD results for B-parameters using NRQCD and improved actions, including detailed scaling and uncertainty analysis.

Findings

B_{B_d}(m_b)=0.84(2)(8)

B_{B_s}/B_{B_d}=1.017(10)(^{+4}_{-0})

B_{S_s}(m_b)=0.87(1)(9)(^{+1}_{-0})

Abstract

We present our recent results for the B-parameters, which parameterize the \Delta B=2 transition amplitudes. Calculations are made in quenched QCD at \beta=5.7, 5.9, and 6.1, using NRQCD for heavy quark and the $O(a)$-improved action for light quark. The operators are perturbatively renormalized including corrections of O(\alpha_s/am_Q). We examine scaling behavior of the B-parameters in detail, and discuss the systematic uncertainties using scatter of results with different analysis procedures adopted. As a result, we find B_{B_d}(m_b)=0.84(2)(8), B_{B_s}/B_{B_d}=1.017(10)(^{+4}_{-0}) and B_{S_s}(m_b)=0.87(1)(9)(^{+1}_{-0}) in the quenched approximation.