Pion couplings to the scalar B meson

Abstract

We present two-flavor lattice QCD estimates of the hadronic couplings $g_{B_0^{\ast }B\pi }$ and $g_{B_1^{\ast }{B}_0^{\ast }\pi }$ that parametrise the non leptonic decays $B_0^{\ast }\to B\pi$ and $B_1^{\ast }\to B_0^{\ast }\pi$. We use CLS two-flavour gauge ensembles. Our framework is the Heavy Quark Effective Theory (HQET) in the static limit and solving a Generalized Eigenvalue Problem (GEVP) reveals crucial to disentangle the $B_0^{\ast }$($B_1^{\ast }$) state from the $B\pi$($B^{\ast }\pi$) state. This work brings us some experience on how to treat the possible contribution from multihadronic states to correlation functions calculated on the lattice, especially when $S$-wave states are involved.

Comments: 12 pages, 10 figures, published version