Bonn 2010 – scientific programme

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HK: Fachverband Physik der Hadronen und Kerne

HK 67: Hadronenstruktur und -spektroskopie XII

HK 67.1: Talk

Friday, March 19, 2010, 14:00–14:15, JUR A

Quark-mass dependence of baryons in QCD with 2+1 flavors — •Thomas R. Hemmert and Andreas Schäfer — Institut für Theoretische Physik, Fakultät Physik, Universität Regensburg

Over the past few years the quark-mass dependence of baryon properties has been studied in detail via Lattice QCD simulations with 2 light quark flavors. For example, the observed quark-mass dependence of the mass of a nucleon is now well understood within the context of baryon chiral perturbation theory (ChPT), which can also correct for extra mass-shifts arising from the finite simulation volume [1].

Currently simulations with 2+1 quark-flavors are one of the frontier research areas in Lattice QCD studies of baryon structure (see e.g. [2,3]). However, all attempts to understand the observed quark-mass dependencies within the context of ChPT have failed so far, as the addition of a third flavor brings in several complications for the effective field theory of low energy QCD. In this talk we present new results [4] on the quark-mass dependencies of the masses of octet baryons. We also explain how we systematically overcome the previous problems of chiral extrapolation studies for baryon observables in the case of 2+1 quark flavors.

References:

[1] e.g. see A. Ali Khan et al., Nucl. Phys. B689, 175 (2004).

[2] S. Dürr et al., Science 322, 1224 (2008).

[3] W. Bietenholz et al., PoS LAT2009:102 (2009).

[4] T.R. Hemmert and A. Schäfer, forthcoming.

This work has been supported by BMBF and DFG.