Understanding the like-sign dimuon charge asymmetry in $p \bar{p}$ collisions

TL;DR

This paper investigates the like-sign dimuon charge asymmetry in proton-antiproton collisions, exploring potential causes and identifying a previously unconsidered standard model source that reduces the discrepancy with observed data.

Contribution

It introduces a new standard model source that partially explains the observed asymmetry, addressing a significant deviation from previous expectations.

Findings

Identified a new standard model contribution affecting the asymmetry

Reduced the discrepancy between measurement and standard model prediction

Suggests further investigation is needed to fully explain the asymmetry

Abstract

The D\O\ collaboration has measured the like-sign dimuon charge asymmetry in $p \bar{p}$ collisions at the Fermilab Tevatron collider. The result is significantly different from the standard model expectation of CP violation in mixing. In this paper we consider the possible causes of this asymmetry and identify one standard model source not considered before. It decreases the discrepancy of the like-sign dimuon charge asymmetry with the standard model prediction, although does not eliminate it completely.