Electromagnetic and spin polarisabilities in lattice QCD

Abstract

We discuss the extraction of the electromagnetic and spin polarisabilities of nucleons from lattice QCD. We show that the external field method can be used to measure all the electromagnetic and spin polarisabilities including those of charged particles. We then turn to the extrapolations required to connect such calculations to experiment in the context of chiral perturbation theory, finding a strong dependence on the lattice volume and quark masses.

7 pages, talk presented at 24th International Symposium on Lattice Field Theory, 23-28 July 2006. To appear in Proceedings of Science