Matter-induced charge symmetry breaking and the pion form factor in nuclear medium

Abstract

Medium modification of the pion form factor has been evaluated in asymmetric nuclear matter (ANM). It is shown that both the shape and the pole position of the pion form factor in dense asymmetric nuclear matter is different from its vacuum counterpart with ρ–ω mixing. This is due to the density and asymmetry-dependent ρ–ω mixing which could even dominate over its vacuum counterpart in matter. Results are presented for an arbitrarily mixing angle. The effect of the in-medium pion factor on experimental observables, e.g., invariant mass distribution of lepton pairs has been demonstrated.