https://doi.org/10.1140/epjc/s10052-019-7254-x
Regular Article - Theoretical Physics
Impacts of radiative corrections on measurements of lepton flavour universality in 
decays
INFN Laboratori Nazionali di Frascati, Via Enrico Fermi, 40, 00044, Frascati, Italy
* e-mail: suzanne.klaver@cern.ch
Received:
28
May
2019
Accepted:
27
August
2019
Published online:
7
September
2019
Radiative corrections to decays may have an impact on predictions and measurements of the lepton flavour universality observables 
and 
. In this paper, a comparison between recent calculations of the effect of soft-photon corrections on and , and corrections generated by the widely used package Photos is given. The impact of long-distance Coulomb interactions, which are not simulated in Photos, is discussed. Furthermore, the effect of high-energy photon emission is studied through pseudo-experiments in an LHCb-like environment. It is found that over- or underestimating these emissions can cause a bias on 
as high as 7%. However, this bias depends on individual analyses, and future high precision measurements require an accurate evaluation of these QED corrections.
© The Author(s), 2019
