On the possibility of a discontinuous quark-mass dependence of baryon octet and decuplet masses

Abstract

We compute the quark-mass dependence of the baryon octet and decuplet masses within the $\chi$-MS scheme at the one-loop level. The results are confronted with recent lattice QCD simulations of the MILC collaboration. A fair reproduction of the quark-mass dependence as suggested by the lattice simulations is obtained up to pion masses of about 700 MeV. Based on the chiral one-loop results we predict that the dependence of the baryon octet and decuplet masses on the quark-masses is discontinuous. Typically the pion-mass dependence is smooth up to about 300 MeV only. This is a consequence of self consistency imposed on the partial summation, i.e. the masses used in the loop functions are identical to those obtained from the baryon self energies. The 'mysterious' quark-mass dependence of the Xi mass predicted by the MILC collaboration is recovered in terms of a discontinuous chiral extrapolation.

Comments: 12 pages, 1 figure, 1 table. 2nd version: corrected typos, clarified conclusions in the summary, results unchanged