Speaker
Prof.
Gastão Krein
(UNESP)
Description
There is a remarkable prediction of QCD that the leptonic decay
constants of the excited states of the pion are dramatically
suppressed relative to that of the ground-state pion - in the
chiral limit, the decay constants of the excited pions are
exactly zero. Although within a quark model perspective a
suppression of a leptonic decay constant for excited states
is expected, as it is proportional to the wave-function at
the origin, there is, however, no a priori reason, within such
a perspective, for the dramatic suppression predicted by QCD.
Lattice computations give conflicting results. In the present talk we
present results of a recent study of the structure of excited pions within
a chiral holographic QCD model; we present results on the leptonic decay
constants of pion's excited states and present new predictions concerning
their quark mass dependence. Comparisons are made with corresponding
results obtained in light-front holography.
Author
Prof.
Gastão Krein
(UNESP)
