Speaker
Description
In this talk we present a lattice determination of the hadronic susceptibilities that, as a consequence of unitarity and analyticity, constrain the form factors entering the semileptonic $b\rightarrow c$ transitions. We evaluate the longitudinal and transverse susceptibilities of the vector, axial and tensor polarization functions at zero momentum transfer from the moments of appropriate two-point correlation functions. The latter are obtained on the lattice employing gauge ensembles of the Extended Twisted Mass Collaboration (ETMC) with $N_f = 2 + 1 + 1$ flavors of Wilson-clover twisted-mass quarks with masses of all the dynamical quark flavors tuned close to their physical values. The simulations are carried out at four values of the lattice spacing, a ≃ 0.057,0.068, 0.080, 0.091 fm, with spatial lattice sizes up to L ≃ 7.6 fm. To allow for a smooth extrapolation to the physical b-quark mass, the heavy-quark mass is simulated directly on the lattice up to ≃3 times the physical charm mass.
| Topical area | Quark and Lepton Flavor Physics |
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