dorsal/arxiv
View SchemaIn-medium omega-meson broadening and S-wave pion annihilation into e^+e^- pairs
| Authors | Gyuri Wolf, Bengt Friman, Madeleine Soyeur |
|---|---|
| Categories | |
| ArXiv ID | nucl-th/9707055 |
| URL | https://arxiv.org/abs/nucl-th/9707055 |
| DOI | 10.1016/S0375-9474(98)00450-3 |
| Journal | Nucl.Phys. A640 (1998) 129-143 |
Abstract
An $\omega$-meson in motion with respect to a nuclear medium can couple to a $\sigma$-meson through a particle-hole excitation. This coupling is large. We investigate its consequences for the width of $\omega$-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 $\omega$-mesons, resulting from the $\omega-\sigma$ transition and the subsequent $2\pi$ decay of the $\sigma$-meson, leads to a substantial broadening of $\omega$-mesons in matter and possibly to an observable effect in experiments measuring the $e^+e^-$ decay of vector mesons produced in nuclei and in relativistic heavy-ion collisions. The inverse process, the s-wave annihilation of pions into $\omega$-mesons decaying into $e^+e^-$ pairs, has in general a much smaller cross section than the corresponding p-wave annihilation through $\rho$-mesons and is expected to contribute rather little to the total $e^+e^-$ pair production in relativistic heavy ion collisions.
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"abstract": "An $\\omega$-meson in motion with respect to a nuclear medium can couple to a\n$\\sigma$-meson through a particle-hole excitation. This coupling is large. We\ninvestigate its consequences for the width of $\\omega$-mesons in matter and for\nthe s-wave annihilation of pions into lepton pairs which can take place in\nrelativistic heavy ion collisions. We find that the two pion decay of\n$\\omega$-mesons, resulting from the $\\omega-\\sigma$ transition and the\nsubsequent $2\\pi$ decay of the $\\sigma$-meson, leads to a substantial\nbroadening of $\\omega$-mesons in matter and possibly to an observable effect in\nexperiments measuring the $e^+e^-$ decay of vector mesons produced in nuclei\nand in relativistic heavy-ion collisions. The inverse process, the s-wave\nannihilation of pions into $\\omega$-mesons decaying into $e^+e^-$ pairs, has in\ngeneral a much smaller cross section than the corresponding p-wave annihilation\nthrough $\\rho$-mesons and is expected to contribute rather little to the total\n$e^+e^-$ pair production in relativistic heavy ion collisions.",
"arxiv_id": "nucl-th/9707055",
"authors": [
"Gyuri Wolf",
"Bengt Friman",
"Madeleine Soyeur"
],
"categories": [
"nucl-th",
"hep-ph"
],
"doi": "10.1016/S0375-9474(98)00450-3",
"journal_ref": "Nucl.Phys. A640 (1998) 129-143",
"title": "In-medium omega-meson broadening and S-wave pion annihilation into e^+e^- pairs",
"url": "https://arxiv.org/abs/nucl-th/9707055"
},
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