The QED nonfactorizable correction to the semileptonic charmed three-body $B$ decays

TL;DR

This paper calculates the nonfactorizable QED corrections to semileptonic B decays involving charm mesons, revealing lepton mass dependence and slight modifications to branching ratios and lepton flavor ratios.

Contribution

It provides a detailed analysis of QED nonfactorizable corrections at the quark level for B to D(*) decays, highlighting their impact on branching ratios and lepton flavor ratios.

Findings

QED corrections are sensitive to charged lepton mass.

QED contributions slightly increase branching ratios.

Ratios R(D(*))_e < R(D(*))_μ are observed.

Abstract

In this paper, the nonfactorizable photonic corrections to the effective four-fermion vertex for the $\overline{B}$ ${\to}$ $D^{({\ast})}$ $+$ ${\ell}^{-}$ $+$ $\bar{\nu}_{\ell}$ decays are considered at the quark level within SM, where ${\ell}$ $=$ $e$, ${\mu}$ and ${\tau}$. It is found that the QED corrections are closely related with the mass of the charged lepton. The QED contributions will enhance branching ratios, which results in the slight reduction of ratios $R(D^{(\ast)})$ and the relationship $R(D^{(\ast)})_{e}$ $<$ $R(D^{(\ast)})_{\mu}$.