Eur. Phys. J. A (2013) 49: 148
https://doi.org/10.1140/epja/i2013-13148-x

Regular Article - Theoretical Physics

The width of the ω meson in the nuclear medium

¹ Departament d’Estructura i Constituents de la Matèria and Institut de Ciències del Cosmos, Universitat de Barcelona, Martí i Franquès 1, E-08028, Barcelona, Spain
² Instituto de Ciencias del Espacio (IEEC/CSIC) Campus Universitat Autònoma de Barcelona, Facultat de Ciències, Torre C5, E-08193, Barcelona, Spain
³ Frankfurt Institute for Advanced Studies (FIAS), Johann Wolfgang Goethe University, Ruth-Moufang-Str. 1, 60438, Frankfurt am Main, Germany
⁴ Research Center for Nuclear Physics (RCNP), Mihogaoka 10-1, 567-0047, Ibaraki, Japan
⁵ Departamento de Física Teórica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigación de Paterna, Aptdo. 22085, E-46071, Valencia, Spain

^* e-mail: ramos@ecm.ub.es

Received: 3 July 2013
Accepted: 27 October 2013
Published online: 26 November 2013

Abstract

We evaluate the width of the ω meson in nuclear matter. We consider the free decay mode of the ω into three pions, which is dominated by ρπ decay, and replace the ρ and π propagators by their medium-modified ones. We also take into account the quasielastic and inelastic processes induced by a vector-baryon interaction dominated by vector meson exchange, as well as the contributions coming from the mechanism with medium-modified K , propagators. We obtain a substantial increase of the ω width in the medium, reaching a value of 121 ± 10 MeV at normal nuclear matter density for an ω at rest, which comes mainly from ωN → ππN, ωNN → πNN processes associated to the dominant ω → ρπ decay mode. The value of the width increases moderately with momentum, reaching values of around 200MeV at 600MeV/c.