In-medium ω-meson broadening and s-wave pion annihilation into e+e− pairs

✍ Scribed by Gyuri Wolf; Bengt Friman; Madeleine Soyeur

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 698 KB
• Volume: 640
• Category: Article
• ISSN: 0375-9474
• DOI: 10.1016/s0375-9474(98)00450-3

✦ Synopsis

An ~o-meson in motion with respect to a nuclear medium can couple to a o'-meson through a particle-hole excitation. This coupling is large. We investigate its consequences for the width of ~o-mesons in matter and for the s-wave annihilation of pions into lepton pairs which can take place in relativistic heavy ion collisions. We find that the two pion decay of w-mesons, resulting from the w-o-transition and the subsequent 27r decay of the o'-meson, leads to a substantial broadening of ~o-mesons in matter and possibly to an observable effect in experiments measuring the e+edecay of vector mesons produced in nuclei and in relativistic heavy-ion collisions. The inverse process, the s-wave annihilation of pions into w-mesons decaying into e+e -pairs, has in general a much smaller cross section than the corresponding p-wave annihilation through p-mesons and is expected to contribute rather little to the total e+e -pair production in relativistic heavy ion collisions. @ 1998 Elsevier Science B.V.