Meson-loop contributions to the rho-omega mass splitting & rho charge radius
Abstract
Contributions of two-pseudoscalar and vector-pseudoscalar meson loops to the rho-omega mass splitting are evaluated in a covariant model based on studies of the Schwinger-Dyson equations of QCD. The role and importance of the different time orderings of the meson loops is analyzed and compared with those obtained within time-ordered perturbation theory. It is shown that each meson loop contributes less than 10% of the bare mass, and decreases as the masses of the intermediate mesons increase beyond approximately m_rho/2. A mass splitting of m_omega - m_rho ~= 25 MeV is obtained from the pi pi, K K(bar), omega pi, rho pi, omega eta, rho eta and K* K channels. The model is then used to determine the effect of the two-pion loop on the rho-meson electromagnetic form factor. It is shown that the inclusion of pion loops increases the rho-meson charge radius by 10%.
Keywords
Cite
@article{arxiv.nucl-th/9904079,
title = {Meson-loop contributions to the rho-omega mass splitting & rho charge radius},
author = {M. A. Pichowsky and Sameer Walawalkar and Simon Capstick},
journal= {arXiv preprint arXiv:nucl-th/9904079},
year = {2009}
}
Comments
20 pages, 10 figures, RevTeX; submitted to Physical Review D