Accumulating evidence for nonstandard leptonic decays of D_s mesons

TL;DR

This paper investigates the discrepancy between observed and predicted leptonic decay rates of D_s mesons, suggesting potential new physics explanations like a charged Higgs or leptoquark.

Contribution

It critically examines the robustness of the standard model prediction and proposes new physics scenarios to explain the observed anomaly.

Findings

Measured decay rates exceed standard model predictions by 3.8 sigma

Discrepancy could be explained by charged Higgs boson or leptoquark

Discussion on the theoretical prediction's robustness

Abstract

The measured rate for D_s -> l nu decays, where l is a muon or tau, is larger than the standard model prediction, which relies on lattice QCD, at the 3.8 sigma level. We discuss how robust the theoretical prediction is, and we show that the discrepancy with experiment may be explained by a charged Higgs boson or a leptoquark.