The static-light baryon spectrum from twisted mass lattice QCD

Abstract

We compute the static-light baryon spectrum by means of Wilson twisted mass lattice QCD using N_f = 2 flavors of sea quarks. As light u/d valence quarks we consider quarks, which have the same mass as the sea quarks with corresponding pion masses in the range 340 MeV < m_PS < 525 MeV, as well as partially quenched s quarks, which have a mass around the physical value. We consider all possible combinations of two light valence quarks, i.e. Lambda, Sigma, Xi and Omega baryons corresponding to isospin I = 0, 1/2, 1 and strangeness S = 0, -1, -2 as well as angular momentum of the light degrees of freedom j = 0, 1 and parity P = +, -. We extrapolate in the light u/d and in the heavy b quark mass to the physical point and compare with available experimental results. Besides experimentally known positive parity states we are also able to predict a number of negative parity states, which have neither been measured in experiments nor previously been computed by lattice methods.