1110.4971 (R. Horsley et al.)

Hyperon sigma terms for 2+1 quark flavours    [PDF]

R. Horsley, Y. Nakamura, H. Perlt, D. Pleiter, P. E. L. Rakow, G. Schierholz, A. Schiller, H. Stüben, F. Winter, J. M. Zanotti

QCD lattice simulations determine hadron masses as functions of the quark
masses. From the gradients of these masses and using the Feynman-Hellmann
theorem the hadron sigma terms can then be determined. We use here a novel
approach of keeping the singlet quark mass constant in our simulations which
upon using an SU(3) flavour symmetry breaking expansion gives highly
constrained (i.e. few parameter) fits for hadron masses in a multiplet. This is
a highly advantageous procedure for determining the hadron mass gradient as it
avoids the use of delicate chiral perturbation theory. We illustrate the
procedure here by estimating the light and strange sigma terms for the baryon
octet.

View original: http://arxiv.org/abs/1110.4971