Project: PLepNuGam - Radiative leptonic decays of light and heavy pseudoscalar mesons from Lattice QCD

Prace Call: 17th
ID: 2018184394, Leader: Roberto Frezzotti
Affiliation: Università degli Studi di Roma "Tor Vergata", IT
Research Field: Fundamental Constituents of Matter
Collaborators: Silvano Simula INFN IT , Nazario Tantalo University of Roma "Tor Vergata" IT , Carsten Urbach University of Bonn DE , Ferenc Pittler University of Bonn DE , Bartosz Kostrzewa University of Bonn DE , Marco Garofalo INFN IT , Guido Martinelli University of Rome "La Sapienza" IT , Francesco Sanfilippo INFN IT , Vittorio Lubicz University of Rome III IT , Cecilia Tarantino University of Rome III IT , Davide Giusti University of Rome III IT
Resource Awarded: 45 Mil. core hours on Marconi - KNL


The search for inconsistencies of the Standard Model of Particle Physics, which would signal the presence of new physics, requires the determination of several hadronic quantities with a high level of precision of the order of O(1%) or even better. This is the case of the leptonic weak decays of mesons, which allow to investigate one of the fun- damental ingredients of the Standard Model, namely the Cabibbo-Kobayashi-Maskawa matrix describing the weak mixing of quark flavors. In the last few years calculations of hadronic observables from first principles, taking systematic errors under very good control, have been carried out through large-scale QCD simulations on the lattice. In order to make further progress lattice simulations must include both electromagnetic and strong isospin-breaking effects and reach the physical pion mass point . Recently a new approach to deal with the lattice determination of the leptonic weak decay rates has been proposed and successfully applied to the case of kaon and pion decays thanks to the PRACE project 2014112693 “QED corrections to meson decay rates in Lattice QCD”. The aim of the present project is to continue the previous project by extending the lattice calculations of the leptonic weak decay rates from the light to the heavy quark sectors. In doing so the emission of real photons, which is always included in the experimental data, will for the first time be calculated from first principles. Moreover the pure (isosymmetric) QCD part of the computation will be improved thanks to new simulations including ensembles at the physical pion mass point.