scholarly journals Quark disconnected diagrams in chiral perturbation theory - the scalar form factor

2012 ◽  
Author(s):  
Andreas Juttner
Keyword(s):  
Perturbation Theory ◽  
Form Factor ◽  
Chiral Perturbation Theory ◽  
Chiral Perturbation ◽  
Scalar Form Factor ◽  
Scalar Form

scholarly journals Equivalence Between Vector Meson Dominance and Unitarised Chiral Perturbation Theory

2015 ◽  
Vol 24 (4) ◽  
pp. 289
Author(s):  
Truong Nguyen Tran ◽  
Le Viet Dung
Keyword(s):  
Perturbation Theory ◽  
Vector Meson ◽  
Chiral Perturbation Theory ◽  
Vector Meson Dominance ◽  
S Wave ◽  
Chiral Perturbation ◽  
Scalar Form Factor ◽  
Scalar Form ◽  
Standard Vector ◽  
The One

It is explicitly shown that either the approximate solution of the integral equation for the inverse of the pion form facto,r or the result of the Pad\(\text{\'e}\) approximant method of resumming the one loop Chiral Perturbation Theory (CPTH) are equivalent to the standard vector meson dominance (VMD) models, using the vector meson coupling to two pseudoscalars given by the KSRF relation. Inconsistencies between the one loop CPTH and its unitarised version (or the VMD model) are pointed out. The situation is better for the CPTH calculation of the scalar form factor and the related S-wave $\pi \pi$ scattering. The branching ratios of \(\tau \to \pi^+ \pi^0 \nu \), \(\tau \to K \pi \nu \), \(\tau \to K^+ \eta \nu\) and $\tau \to K^+ \bar{K^0} \nu\) using only two inputs as the \(\rho\) and \(K^*\) masses, or the two corresponding rms radii, agree with the experimental data. Using the same number of parameters, the corresponding one loop CPTH calculation cannot explain the $\tau$ data.

scholarly journals Taylor's Series and Dispersion Relation Analyses of the Vector Pion Form Factor and their Comparison with Perturbative and Non Perturbative Calculations

2015 ◽  
Vol 25 (1) ◽  
pp. 21
Author(s):  
Truong Nguyen Tran
Keyword(s):  
Experimental Data ◽  
Perturbation Theory ◽  
Form Factor ◽  
Dispersion Relation ◽  
Momentum Transfer ◽  
Chiral Perturbation Theory ◽  
Pion Form Factor ◽  
P Wave ◽  
Chiral Perturbation ◽  
Taylor’S Series

The first three coefficients of the Taylor's series expansion of the vevtor pion form factor as a function of the momentum transfer are evaluated using the experimental data on the pion form factor and the P-wave \(\pi\pi\) phase shifts. The real part of the form factor as a function of energy is also calculated by dispersion relation. Comparisons there results with Chiral Perturbation Theory and unitarized models are given.

scholarly journals The electric dipole form factor of the nucleon in chiral perturbation theory to sub-leading order

2011 ◽  
Vol 696 (1-2) ◽  
pp. 97-102 ◽  
Author(s):  
E. Mereghetti ◽  
J. de Vries ◽  
W.H. Hockings ◽  
C.M. Maekawa ◽  
U. van Kolck
Keyword(s):  
Perturbation Theory ◽  
Form Factor ◽  
Chiral Perturbation Theory ◽  
Electric Dipole ◽  
Leading Order ◽  
Chiral Perturbation ◽  
Dipole Form Factor ◽  
Dipole Form
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