Chandrasekharan, S; Strouthos, CG, *Connecting lattice QCD with chiral perturbation theory at strong coupling*,
Physical Review D: Particles, Fields, Gravitation and Cosmology, vol. 69 no. 9
(2004),
pp. 091502 [doi] .
**Abstract:**

*We study the difficulties associated with detecting chiral singularities predicted by chiral perturbation theory (ChPT) in lattice QCD. We focus on the physics of the remnant O(2) chiral symmetry of staggered fermions in the strong coupling limit using the recently discovered directed path algorithm. Since it is easier to look for powerlike singularities as compared to logarithmic ones, our calculations are performed at a fixed finite temperature in the chirally broken phase. We show that the behavior of the chiral condensate, the pion mass, and the pion decay constant are all consistent with the predictions of ChPT for small masses. However, in order to demonstrate this we need quark masses that are much smaller (in lattice units) than those typically used in dynamical QCD simulations. We also need to use higher order terms in the chiral expansion to fit our data. © 2004 The American Physical Society.*