Heavy flavour precision physics from Nf = 2 + 1 + 1 lattice simulations

A Bussone,N Carrasco,P Dimopoulos,R Frezzotti,P Lami,V Lubicz,F Nazzaro,E Picca,L Riggio,G.C Rossi,F Sanfilippo,S Simula,C Tarantino

doi:10.1016/j.nuclphysbps.2015.09.265

Abstract

We present precision lattice calculations of the pseudoscalar decay constants of the charmed sector as well as determinations of the bottom quark mass and its ratio to the charm quark mass. We employ Nf=2+1+1 dynamical quark gauge configurations generated by the European Twisted Mass Collaboration, using data at three values of the lattice spacing and pion masses as low as 210 MeV. Strange and charm sea quark masses are close to their physical values.

Highlights

Physical processes in the heavy quark sector offer the possibility to get some of the more stringest tests of the Standard Model and to search for possible footprints of New Physics dynamics, by directly challenging the unitarity constraints of the CKM matrix.Lattice QCD has already entered the precision era as the accuracy of numerical computations is becoming comparable to that of experiments
Considerable progress has been recently made in flavour physics at the b mass, with the help of both effective theories approaches and thanks to the implementation of some innovative methods. All these progresses have allowed the determination of a number of B-physics parameters with controlled systematic uncertainties
In Ref. [9] we have presented our computation for the quark masses of the light mu/d(MS, 2 GeV) = 3.70(17) MeV, strange ms(MS, 2 GeV) = 99.6(4.1) MeV and charm mc(MS, mc) = 1.348(42) GeV, which are determined by using the experimental values of the pion, kaon and D masses, respectively

Summary

Introduction

Physical processes in the heavy quark sector offer the possibility to get some of the more stringest tests of the Standard Model and to search for possible footprints of New Physics dynamics, by directly challenging the unitarity constraints of the CKM matrix. Considerable progress has been recently made in flavour physics at the b mass, with the help of both effective theories approaches and thanks to the implementation of some innovative methods. All these progresses have allowed the determination of a number of B-physics parameters (e.g. mb, fB and fBs ) with controlled systematic uncertainties. Lattice methods are an invaluable tool to obtain direct determinations of hadronic quantities relevant for the computation of many of the so called golden plated processes such as decay constants, form factors and bag parameters. The European Twisted Mass Collaboration (ETMC) has undertaken an extensive program of heavy quark physics calculations on the lattice using two and four dynamical flavours.

Lattice setup

Charmed decay constants