The pion mass in finite volume
Institute for Theoretical Physics, University of Bern, 3012, Bern, Switzerland
2 DESY Zeuthen, 15738, Zeuthen, Germany
We determine the relative pion mass shift due to the finite spatial extent L of the box by means of two-flavor chiral perturbation theory and the one-particle Lüscher formula. We use as input the expression for the infinite volume forward scattering amplitude up to next-to-next-to-leading order and can therefore control the convergence of the chiral series. A comparison to the full leading order chiral expression for the pion mass in finite volume allows us to check the size of subleading terms in the large-L expansion.
© Springer-Verlag, 2004