Pion Electromagnetic Form Factor and rho-meson Mass Shift at Finite Density

作者：Nam Seung il^*; Kim Hyun Chul

来源：Journal of the Korean Physical Society, 2011, 59(2): 217-223.

DOI：10.3938/jkps.59.217

• rho-meson mass shift
• Finite density
• Pion electromagnetic charge radius
• Non local chiral quark model
• Instanton vacuum

We investigate the pion electromagnetic form factor and the mass dropping of the rho meson at finite density. We first calculate the pion electromagnetic form factor and the corresponding charge radii within the framework of the nonlocal chiral quark model from the instanton vacuum both at zero and finite densities. In order to relate the change in the pion charge radius to that. of the rho-meson mass at finite density, we employ the vector-meson dominance for the pion electromagnetic form factor. The pion charge radius turns out to get larger as the quark chemical potential increases. As a result, the rho-meson mass falls off as the quark chemical potential grows and is found to drop by about 10% at normal nuclear matter density: m(rho)(*)/m(rho) approximate to 1 - 0.12 mu(B)/mu(0), which is compatible to the results of the measurement at the KEK recently.

• 出版日期2011-8