Semileptonic Mixing Asymmetry Measurements of Adsl and Assl

TL;DR

This paper discusses measurements of semileptonic mixing asymmetries in B mesons, highlighting a significant deviation from Standard Model predictions by the D0 collaboration and analyzing the implications for new physics.

Contribution

It presents the D0 measurement of AbSL deviating from the Standard Model and combines various experimental results to constrain new physics explanations.

Findings

D0's AbSL measurement exceeds Standard Model expectations by 3.9 sigma.

World averages of AdSL and AsSL align with Standard Model predictions.

Combined data tightly restricts new physics scenarios explaining the D0 anomaly.

Abstract

Standard Model predictions of the CP violation in the mixing of B0d and B0s mesons are beyond the present experimental sensitivity, any observation would be therefore a hint of new physics. The D0 collaboration measures a value of the semileptonic mixing asymmetry for a mixture of B0d and B0s mesons, AbSL, which misses the Standard Model expectation by 3.9 standard deviations. The world averages of the flavor specific measurements of the semileptonic asymmetries for B0d and B0s mesons, AdSL and AsSL, are instead in agreement with the Standard Model. The combination of the various AqSL (q=d, s) measurements and the recent LHCb results on B0s -> J/psi phi have placed tight bounds on the hypothesis of new physics which can explain the D0 result.