Staggered Chiral Perturbation Theory for Neutral B Mixing

TL;DR

This paper presents a one-loop calculation of B meson mixing within staggered chiral perturbation theory, accounting for both Standard Model and beyond-the-Standard Model operators, highlighting the importance of lattice operator representations.

Contribution

It provides a detailed analysis of B mixing calculations using staggered chiral perturbation theory, including the effects of wrong-spin operators and their continuum limit behavior.

Findings

Wrong-spin operators' contributions vanish in the continuum limit.

The lattice operator representation significantly impacts the calculation.

Relation between staggered and naive fermions is crucial.

Abstract

I describe a calculation of B meson mixing at one-loop in staggered chiral perturbation theory, for the complete set of Standard Model and beyond-the-Standard Model operators. The particular lattice representation of the continuum operators used by the Fermilab Lattice/MILC collaborations (and earlier by the HPQCD collaboration) turns out to be important, and results in the presence of "wrong-spin" operators, whose contributions however vanish in the continuum limit. The relation between staggered and naive fermions also plays a key role.