B-meson spectroscopy in HQET at order1/m

Abstract

We present a study of the B spectrum performed in the framework of heavy quark effective theory expanded to next-to-leading order in $1/{m}_{\mathrm{b}}$ and nonperturbative in the strong coupling. Our analyses have been performed on ${N}_{\mathrm{f}}=2$ lattice gauge field ensembles corresponding to three different lattice spacings and a wide range of pion masses. We obtain the ${\mathrm{B}}_{\mathrm{s}}$-meson mass and hyperfine splittings of the B- and ${\mathrm{B}}_{\mathrm{s}}$-mesons that are in good agreement with the experimental values and examine the mass difference ${m}_{{\mathrm{B}}_{\mathrm{s}}}\ensuremath{-}{m}_{\mathrm{B}}$ as a further cross-check of our previous estimate of the b-quark mass. We also report on the mass splitting between the first excited state and the ground state in the B and ${\mathrm{B}}_{\mathrm{s}}$ systems.