The static-light baryon spectrum from twisted mass lattice QCD

TL;DR

This study uses twisted mass lattice QCD to compute the static-light baryon spectrum, extrapolating to physical quark masses and predicting new negative parity states not previously observed or calculated.

Contribution

It provides the first lattice QCD predictions for negative parity static-light baryon states and performs a comprehensive spectrum analysis with extrapolation to physical quark masses.

Findings

Predicted several negative parity baryon states.

Extrapolated results agree with known experimental data.

Extended the spectrum analysis to include various isospin and strangeness configurations.

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.