22-27 March 2015
Hotel do Bosque
Brazil/East timezone

## Decay constants of the pion and its excitations in holographic QCD

24 Mar 2015, 15:30
30m
Hotel do Bosque

#### Hotel do Bosque

Rodovia Mário Covas (Rio-Santos) BR - 101 Sul, Km 533, Angra dos Reis, RJ, Brazil
Oral presentation Field theoretical approaches to QCD

### 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.

### Primary author

Prof. Gastão Krein (UNESP)

 Slides