INFN - LABORATORI NAZIONALI DI FRASCATI |

SEMINAR
Pions and kaons have double nature: the chiral dynamics of Nambu-Goldstone
bosons together with the usual string dynamics common to all mesons. To uncover
the interplay of both dynamics the effective chiral Lagrangian is derived
from the QCD Lagrangian using the Field Correlator method and the ion self-energy
(mass) operator is written explicitly. The latter contains an infinite number
of poles, but normalized to zero at zero momentum because of spontaneous
chiral symmetry breaking. As a result one obtains the Gell-Mann-Oakes-Renner
relation for the ground state pion and (slightly shifted by chiral dynamics)
the usual spectrum of radially excited pions starting with pi(1300). |