Short-lived ϕ mesons

Abstract

We use effective hadronic field theory to study in-medium properties of the ϕ meson. The dominant decay channels and ϕ → πρ are modelled using an SU(3) chiral Lagrangian with normal and abnormal parities. The ϕ self-energy is approximated to one-, two- and even three-loop order in the strong coupling. Effects of modified spectral functions for π, K, ρ and ϕ are also included in the calculation. This allows us to study in-medium decay of phi mesons into (in-medium) kaon-pair daughters and (in-medium) πρ pairs. The results point to the possibility of rather short-lived ϕ, short enough to decay inside the fireball in relativistic heavy ion collisions. Implications relevant for the NA49 and NA50 experimental results, recently dubbed the ‘ϕ puzzle’, are discussed.