scholarly journals Pion distribution amplitude and the pion-photon transition form factor in a nonlocal chiral quark model

2014 ◽  
Vol 89 (5) ◽  
Author(s):  
D. Gómez Dumm ◽  
S. Noguera ◽  
N. N. Scoccola ◽  
S. Scopetta
Keyword(s):  
Form Factor ◽  
Quark Model ◽  
Transition Form Factor ◽  
Distribution Amplitude ◽  
Chiral Quark Model ◽  
Transition Form ◽  
Photon Transition

scholarly journals Chiral anomaly transition form factor of γ → 3π in nonlocal quark model

2019 ◽  
Vol 204 ◽  
pp. 02001
Author(s):  
Alexey Zhevlakov
Keyword(s):  
Form Factor ◽  
Quark Model ◽  
Transition Form Factor ◽  
Local Limit ◽  
Gamma Transition ◽  
Chiral Anomaly ◽  
Chiral Quark Model ◽  
Transition Form

Chiral anomaly of gamma transition into three pions are studied in a framework of nonlocal chiral quark model. In the local limit the result is in agreement with chiral perturbative theory and reproducesWess-Zumino-Witten anomaly. Transition form factor of gamma into three pions in nonlocal quark model has a correction which vanishes in local limit.

A COMPREHENSIVE ANALYSIS OF THE PION–PHOTON TRANSITION FORM FACTOR IN THE LEADING ORDER APPROXIMATION

2007 ◽  
Vol 22 (18) ◽  
pp. 3065-3086 ◽  
Author(s):  
TAO HUANG ◽  
XING-GANG WU
Keyword(s):  
Experimental Data ◽  
Form Factor ◽  
Transition Form Factor ◽  
Order Approximation ◽  
Comprehensive Analysis ◽  
Distribution Amplitude ◽  
Leading Order ◽  
Transition Form ◽  
Photon Transition ◽  
Fock State

We perform a comprehensive analysis of the pion–photon transition form factor Fπγ(Q2) involving the transverse momentum corrections in the leading order approximation with the present CLEO experimental data, in which the contributions beyond the leading Fock state have been taken into consideration. As is well known, the leading Fock-state contribution dominates of Fπγ(Q2) at large momentum transfer (Q2) region. One should include the contributions beyond the leading Fock state in small Q2 region. In this paper, we construct a phenomenological expression to estimate the contributions beyond the leading Fock state based on its asymptotic behavior at Q2→0. Our present theoretical results agree well with the experimental data in the whole Q2 region. Then, we extract some useful information of the pionic leading twist-2 distribution amplitude (DA) by comparing our results of Fπγ(Q2) with the CLEO data. By taking best fit, we have the distribution amplitude moments, [Formula: see text] and all of higher moments, which are closed to the asymptotic-like behavior of the pion wave function.

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