Impacts of radiative corrections on measurements of lepton flavour universality in $B\to D\ell {\nu }_{\ell }$ decays

Abstract

Radiative corrections to $B\to D\ell {\nu }_{\ell }$ decays can have an impact on predictions and measurements of the lepton universality ratios $\mathcal{R}(D^{+})$ and $\mathcal{R}(D^0)$. These proceedings summarise a study on the comparison between recent calculations of soft-photon corrections on these ratios and the corrections simulated by the PHOTOS package. Also the impact of Coulomb interactions, not simulated in PHOTOS, is discussed. Using pseudo-experiments, the effect of high-energy photon emission is studied in an LHCb-like environment, showing a bias of up to 7\% on measurements of $\mathcal{R}(D)$.

Comments: 4 pages, 11 figures, proceedings of the 2019 Conference on Flavor Physics and CP Violation (FPCP2019), based on the work in arXiv:1905.02702