QCD lattice simulations yield hadron masses as functions of the quark masses. From the gradients of the hadron masses the sigma terms can then be determined. We consider here dynamical 2+1 flavour simulations, in which we start from a point of the flavour symmetric line and then keep the singlet or average quark mass fixed as we approach the physical point. This leads to highly constrained fits for hadron masses in a multiplet. The gradient of this path for a hadron mass then gives a relation between the light and strange sigma terms. A further relation can be found from the change in the singlet quark mass along the flavour symmetric line. This enables light and strange sigma terms to be estimated for the baryon octet.
@article{arxiv.1112.1883,
title = {Nucleon sigma terms for 2+1 quark flavours},
author = {R. Horsley and Y. Nakamura and H. Perlt and D. Pleiter and P. E. L. Rakow and G. Schierholz and A. Schiller and H. Stüben and F. Winter and J. M. Zanotti},
journal= {arXiv preprint arXiv:1112.1883},
year = {2011}
}
Comments
7 pages, 3 figures. Talk presented at the XXIX International Symposium on Lattice Field Theory (Lattice 2011), July 10-16, 2011, Squaw Valley, Lake Tahoe, California, USA