2022/12/17 by Leskovec, Luka, Meinel, Stefan, Petschlies, Marcus +4
#FOS: Physical sciences #High Energy Physics - Lattice (hep-lat) #High Energy Physics - Phenomenology (hep-ph)
paper · doi:10.48550/arxiv.2212.08833
Vub is the smallest and least known of all CKM matrix elements; the community currently determines its magnitude primarily through the exclusive process B→πℓν. Here we present our progress toward a lattice QCD determination of the Vub matrix element from a novel transition -- B→ππℓν process, where the ππ system is in a P wave and scattering features the ρ(770) resonance as an enhancement. We perform our calculation on Nf=2+1 isotropic clover fermions on a lattice of L≈ 3.6 fm and a pion mass of ≈ 320 MeV; for the b-quark we use the anisotropic clover action. After a brief overview of the theoretical framework, we will discuss some preliminary results.