B^0_s and B^0 Mixing in the Standard Model and Beyond: A Progress Report

TL;DR

This paper reviews recent progress in calculating B meson mixing matrix elements within the Standard Model and beyond, using lattice QCD techniques with specific actions and ensembles, providing preliminary results and error estimates.

Contribution

It presents updated lattice QCD calculations of B meson mixing matrix elements, including beyond Standard Model operators, with new preliminary results and error analysis.

Findings

Preliminary B_s mixing matrix results at 0.12 fm lattice spacing.

Inclusion of SUSY basis of four-quark operators.

Error estimates for future precision improvements.

Abstract

We give a progress report on the calculation of B meson mixing matrix elements, focusing on contributions that could arise beyond the Standard Model. The calculation uses asqtad (light quark) and Fermilab (heavy quark) valence actions and MILC ensembles with 2+1 flavors of asqtad sea quarks. We report preliminary B^0_s fit results, at a lattice spacing of 0.12 fm, for the SUSY basis of effective four-quark mixing operators and include an estimate for the final error budget.