Speaker
Simone Romiti
Description
We present a Lattice calculation of the mass difference between neutron and proton, obtained at 1st order in the $QED$ coupling $\alpha_{EM}$ and in the mass difference between $u$ and $d$ quarks $\frac{m_d-m_u}{\Lambda_{QCD}}$. We adopt a purely hadronic scheme to renormalize the theory and to separate the $QED$ and strong $IB$ contributions.
The simulation is carried out using the ETMC gauge configurations with $N_f=2+1+1$ dynamical quarks. We extrapolate among $3$ values of the lattice spacing and pion masses in the range \mbox{$M_\pi \simeq 200 - 450 $ MeV}.
