### Abstract

We present a relativistic and unitary approach to pion- and photon-nucleon scattering taking into account the πN, ρN, ωN, ηN, πΔ, Λ and K∑ channels. Our scheme dynamically generates the s- and d-wave baryon resonances N(1535), N(1650), N(1520) and N(1700) and as well as Δ(1620) and Δ(1700) in terms of quasi-local two-body interaction terms. The description of photon-induced processes is based on a generalized vector-meson dominance assumption which directly relates the electromagnetic quasi-local 4-point interaction vertices to the corresponding vertices involving the ρ and ω fields. We obtain a fair description of the experimental data relevant for the properties of slow vector mesons in nuclear matter. The resulting s-wave ρ- and ω-meson nucleon scattering amplitudes, which define the leading density modification of the ρ- and ω-meson spectral functions in nuclear matter, are presented. We find a repulsive energy shift for the ω meson at small nuclear density but predict considerable strength in resonance-hole like ω-meson modes. Compared to previous calculations our result for the ρ-meson spectral function shows a significantly smaller in-medium effect. This reflects a fairly small coupling strength of the N(1520) resonance to the ρN channel.

Original language | English |
---|---|

Pages (from-to) | 152-159 |

Number of pages | 8 |

Journal | Progress of Theoretical Physics Supplement |

Volume | 149 |

Publication status | Published - 2003 |

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### ASJC Scopus subject areas

- Physics and Astronomy(all)

### Cite this

*Progress of Theoretical Physics Supplement*,

*149*, 152-159.

**From Meson- And Photon-Nucleon Scattering to Vector Mesons in Nuclear Matter.** / Wolf, G.; Lutz, M. F M; Friman, B.

Research output: Contribution to journal › Article

*Progress of Theoretical Physics Supplement*, vol. 149, pp. 152-159.

}

TY - JOUR

T1 - From Meson- And Photon-Nucleon Scattering to Vector Mesons in Nuclear Matter

AU - Wolf, G.

AU - Lutz, M. F M

AU - Friman, B.

PY - 2003

Y1 - 2003

N2 - We present a relativistic and unitary approach to pion- and photon-nucleon scattering taking into account the πN, ρN, ωN, ηN, πΔ, Λ and K∑ channels. Our scheme dynamically generates the s- and d-wave baryon resonances N(1535), N(1650), N(1520) and N(1700) and as well as Δ(1620) and Δ(1700) in terms of quasi-local two-body interaction terms. The description of photon-induced processes is based on a generalized vector-meson dominance assumption which directly relates the electromagnetic quasi-local 4-point interaction vertices to the corresponding vertices involving the ρ and ω fields. We obtain a fair description of the experimental data relevant for the properties of slow vector mesons in nuclear matter. The resulting s-wave ρ- and ω-meson nucleon scattering amplitudes, which define the leading density modification of the ρ- and ω-meson spectral functions in nuclear matter, are presented. We find a repulsive energy shift for the ω meson at small nuclear density but predict considerable strength in resonance-hole like ω-meson modes. Compared to previous calculations our result for the ρ-meson spectral function shows a significantly smaller in-medium effect. This reflects a fairly small coupling strength of the N(1520) resonance to the ρN channel.

AB - We present a relativistic and unitary approach to pion- and photon-nucleon scattering taking into account the πN, ρN, ωN, ηN, πΔ, Λ and K∑ channels. Our scheme dynamically generates the s- and d-wave baryon resonances N(1535), N(1650), N(1520) and N(1700) and as well as Δ(1620) and Δ(1700) in terms of quasi-local two-body interaction terms. The description of photon-induced processes is based on a generalized vector-meson dominance assumption which directly relates the electromagnetic quasi-local 4-point interaction vertices to the corresponding vertices involving the ρ and ω fields. We obtain a fair description of the experimental data relevant for the properties of slow vector mesons in nuclear matter. The resulting s-wave ρ- and ω-meson nucleon scattering amplitudes, which define the leading density modification of the ρ- and ω-meson spectral functions in nuclear matter, are presented. We find a repulsive energy shift for the ω meson at small nuclear density but predict considerable strength in resonance-hole like ω-meson modes. Compared to previous calculations our result for the ρ-meson spectral function shows a significantly smaller in-medium effect. This reflects a fairly small coupling strength of the N(1520) resonance to the ρN channel.

UR - http://www.scopus.com/inward/record.url?scp=0042166063&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0042166063&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0042166063

VL - 149

SP - 152

EP - 159

JO - Progress of Theoretical Physics

JF - Progress of Theoretical Physics

SN - 0033-068X

ER -