Tuesday, April 16, 2013

1304.3888 (Chuan Li et al.)

Minimal Ward-Takahashi Vertices and Pion Light Cone Distribution
Amplitudes from Gauge Invariant, Nonlocal, Dynamical Quark Model
   [PDF]

Chuan Li, Shao-Zhou Jiang, Qing Wang
The gauge-invariant, nonlocal, dynamical quark model is proved to generate the minimal vertices which satisfy the Ward-Takahashi identities. In the chiral limit, the momentum-dependent quark self-energy results in a flat-like form with some end point delta-funtions for the light-cone pion distribution amplitudes, similarly found in the Nambu Jona-Lasino model with constant constituent mass. The leading order nonzero pion and current quark masses corrections lead concave type asymptotic-like form modifications to twist-2 pion distribution amplitude with end point pillars and twist-3 tensor pion distribution amplitude above the flat-like form backgrounds. A by-product of our investigation shows that the variable u appearing in pion light-cone distribution amplitudes is just the standard Feynman parameter in the Feynman parameter integrals; also chiral perturbation works well for these amplitudes.
View original: http://arxiv.org/abs/1304.3888

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