出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We calculate the electromagnetic form factor of the pion in quenched lattice QCD. The nonperturbatively
improved Sheikoleslami-Wohlert lattice action together with the O(a) improved
current are used to reduce discretisation effects. We obtain form factors for pion masses as low
as mp = 360 MeV. From the low Q2 behaviour, we extract the pion radius and use (quenched)
chiral perturbation theory to extrapolate the result towards the physical pion mass. In addition,
we present the first finite temperature lattice results for the matrix element of the electromagnetic
current between pion states and discuss possible differences to the zero temperature case.
