Chiral behaviour of Delta B = 2 and Delta C =2 matrix elements

TL;DR

This paper studies how light-quark mass and volume affect matrix elements relevant for B and D meson mixing, revealing complex chiral extrapolation behaviors especially beyond the Standard Model.

Contribution

It provides new insights into the chiral behavior of four-fermion operators for heavy meson mixing, highlighting complexities in extrapolations beyond the Standard Model.

Findings

Chiral extrapolations are more complex for B and D mixing beyond the Standard Model.

Matrix elements depend significantly on light-quark mass and volume.

Implications for lattice QCD calculations of meson mixing.

Abstract

We investigate the light-quark mass and spatial volume dependence of matrix elements of Delta B = 2 and Delta C = 2 four-fermion operators. These operators are relevant for Neutral B(s) and D mixing in and beyond the Standard Model. An important conclusion of this work is that the chiral extrapolations for matrix elements of heavy-light meson mixing beyond the Standard Model are more complicated than that for the Standard Model mixing matrix elements.