# 36th Annual International Symposium on Lattice Field Theory

Jul 22 – 28, 2018
Kellogg Hotel and Conference Center
EST timezone

## Hypercubic effects in semileptonic decays of heavy mesons, toward $B \to \pi \ell\nu$ with Nf=2+1+1 Twisted fermions

Jul 27, 2018, 4:30 PM
20m
103 (Kellogg Hotel and Conference Center)

### 103

#### Kellogg Hotel and Conference Center

219 S Harrison Rd, East Lansing, MI 48824
Weak Decays and Matrix Elements

### Speaker

Dr Lorenzo Riggio (INFN Sez. Roma Tre)

### Description

We present a preliminary study toward a lattice determination of the vector and scalar form factors of the $B \to \pi \ell \nu$ semileptonic decays. We compute the form factors relative to the transition between pseudo-scalar heavy mesons, with masses above the D-mass, and the pion. We simulate the valence heavy quark with a mass in the range $m_c < m_h < 2m_c$. Lorentz symmetry breaking due to hypercubic effects is clearly observed in the data and included in the decomposition of the current matrix elements in terms of additional form factors. We discuss the size of this breaking as the parent-meson mass increases. Our analysis is based on the gauge configurations produced by the European Twisted Mass Collaboration with $N_f = 2 + 1 + 1$ flavors of dynamical quarks. We simulated at three different values of the lattice spacing and with pion masses as small as 210 MeV.

### Primary author

Dr Lorenzo Riggio (INFN Sez. Roma Tre)

### Co-authors

Dr Cecilia Tarantino (Università di Roma Tre) Dr Giorgio Salerno (Università di Roma Tre and LPT Orsay) Dr Silvano Simula (INFN Sez. Roma Tre) Prof. Vittorio Lubicz (Università di Roma Tre)

 Slides