arXiv subjects
Publications and source records attributed to Sameer Walawalkar.
We include the electromagnetic currents from fermion degrees of freedom in the equations of motion for electroweak MSSM with a right-handed Stop that we have recently investigated. It is found that near the surface of the bubble walls there are important effects on the electromagnetic fields produced during bubble nucleation.
Starting from the QCD Lagrangian and the surface tension of QCD bubbles we derive the critical size of bubbles, the nucleation probability and the nucleation site separation distance. We find the separation of sites is more than an order of magnitude larger than previous QCD model estimates, which could lead to observable effects.
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%.