Speaker: Paulo F. Bedaque (University of Maryland)
Title:
Restless Pions: Orbifold Boundary Conditions and Noise Suppression in Lattice QCD
Abstract:
The study of one or more baryons in lattice QCD is severely hindered
by the exponential decay in time of the signal-to-noise ratio. The
rate at which the signal-to-noise decreases is a function of the the
pion mass. More precisely, it depends on the minimum allowed pion
energy in the box, which, for periodic boundary conditions, is equal
to its mass. We propose a set of boundary conditions, given by a
"parity orbifold'' construction, which eliminates the zero momentum
pion modes, raising the minimum pion energy without altering the
QCD ground state, and thereby improving the signal-to-noise ratio of
(multi)-baryon correlation functions at long Euclidean times. We
discuss variations of these "restless pions" boundary conditions and
focus on their impact on the study of nuclear forces.