出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We performa non-perturbative study of the two-photon decay of neutral pion using 2+1 flavors of overlap fermions at pion masses ranging from mp = 540 to 300MeV, at a lattice spacing a = 0.11 fm and at a lattice size L3 ×T/a4 = 163 ×48. Using the all-to-all quark propagator technique, we construct the relevant three-point functions. Using two different methods we compute the p 0!g g transition formfactor in both space-like and time-like domains. Extrapolating the form factor to the on-shell photon limit, we find that the results from the two methods are consistent.
