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Resonant modes in the nuclear medium and nucleus-nucleus collisions

Abstract

The properties of the Delta-resonance are investigated in infinite nuclear matter, in the semi-infinite slab model and in charge exchange reactions on a finite nucleus. Also nuclear fragmentation and interferometry experiments have been analysed. In infinite nuclear matter the decay of the {Delta}-resonance into a nucleon and a general spin-isospin mode consisting of pions ({rho}-mesons), NN{sup -1} and {Delta}N{sup -1} states is calculated. For the case of no width of the {Delta}s in the spin-isospin mode, partial contributions to the {Delta}-width from different {Delta}-decay channels are presented. The decay of the spin-isospin mode at a nuclear surface is studied, taking into account the in-medium properties of the {Delta}. In the semi-infinite slab model the contributions to the total surface response from different decay channels NN, N{pi},{pi} in (p,n) and ({sup 3}He,T) reactions, are calculated. Good qualitative agreement with recent exclusive experiments is achieved. The {Delta}-nucleus optical potential from microscopic calculations in nuclear matter is used to study the effects of its energy dependence in (p,n) and ({sup 3}He,T) reactions. The neutron or triton spectrum is calculated via response function of a finite nucleus. Only very small effects, 1-2%, were found for the ({sup 3}He,T) reaction. The emission of low energy  More>>
Authors:
Publication Date:
Aug 01, 1993
Product Type:
Thesis/Dissertation
Report Number:
LUND-MPH-93-07
Reference Number:
SCA: 662340; PA: AIX-25:012422; EDB-94:040851; ERA-19:010754; NTS-94:018200; SN: 94001153091
Resource Relation:
Other Information: TH: Diss. (TeknD).; PBD: Aug 1993
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; N BARYONS; NUCLEON-NUCLEON INTERACTIONS; DECAY; EXPERIMENTAL DATA; NUCLEAR FRAGMENTATION; SPIN; 662340; HADRON INTERACTIONS
OSTI ID:
10127405
Research Organizations:
Lund Univ. (Sweden). Dept. of Mathematical Physics
Country of Origin:
Sweden
Language:
English
Other Identifying Numbers:
Other: ON: DE94614594; ISBN 91-628-0980-6; TRN: SE9300315012422
Availability:
OSTI; NTIS; INIS
Submitting Site:
SWDN
Size:
27 p.
Announcement Date:
Jul 04, 2005

Citation Formats

Helgesson, J. Resonant modes in the nuclear medium and nucleus-nucleus collisions. Sweden: N. p., 1993. Web.
Helgesson, J. Resonant modes in the nuclear medium and nucleus-nucleus collisions. Sweden.
Helgesson, J. 1993. "Resonant modes in the nuclear medium and nucleus-nucleus collisions." Sweden.
@misc{etde_10127405,
title = {Resonant modes in the nuclear medium and nucleus-nucleus collisions}
author = {Helgesson, J}
abstractNote = {The properties of the Delta-resonance are investigated in infinite nuclear matter, in the semi-infinite slab model and in charge exchange reactions on a finite nucleus. Also nuclear fragmentation and interferometry experiments have been analysed. In infinite nuclear matter the decay of the {Delta}-resonance into a nucleon and a general spin-isospin mode consisting of pions ({rho}-mesons), NN{sup -1} and {Delta}N{sup -1} states is calculated. For the case of no width of the {Delta}s in the spin-isospin mode, partial contributions to the {Delta}-width from different {Delta}-decay channels are presented. The decay of the spin-isospin mode at a nuclear surface is studied, taking into account the in-medium properties of the {Delta}. In the semi-infinite slab model the contributions to the total surface response from different decay channels NN, N{pi},{pi} in (p,n) and ({sup 3}He,T) reactions, are calculated. Good qualitative agreement with recent exclusive experiments is achieved. The {Delta}-nucleus optical potential from microscopic calculations in nuclear matter is used to study the effects of its energy dependence in (p,n) and ({sup 3}He,T) reactions. The neutron or triton spectrum is calculated via response function of a finite nucleus. Only very small effects, 1-2%, were found for the ({sup 3}He,T) reaction. The emission of low energy (1A to 6A MeV) medium size (Z=3-12) fragments in {sup 16}O+{sup 37}Al reactions at 94A MeV, has been studied. The numerical implementation normally used to simulate the BUU equation has been used to construct a more classical cascade model that could also give fragment distributions. With this model the gross features of the experimental data have been reproduced. Small angle pp-, nn- and pn-correlation functions from 30A {sup 40}Ar+{sup 197}Au reactions have been studied using evaporation, BUU and BUU+evaporation as sources for generating `free` particles. Also here the gross features were reproduced. 32 refs.}
place = {Sweden}
year = {1993}
month = {Aug}
}