Abstract
Hadronic spin-excitations in finite Fermi systems are investigated by studying inelastic proton- and antiproton-nucleus scattering in doubly magic nuclei ({sup 12}C, 4{sup 0}Ca, {sup 48}Ca, {sup 208}Pb). The Random-Phase-Approximation (RPA) and the Distorted-Wave-Born-Approximation (DWBA) are used to describe the nuclear structure and reaction respectively. The possibility of a low-energy octupole resonance (LEOR) in {sup 208}Pb, which exhausts a significant fraction of the energy weighted sum rule, is investigated. It is found that the sum-rule fraction of {proportional_to} 15% seen in (p,p`) reactions depends sensitively on the strength of the isovector projectile-target nucleus interaction. To study spin-excitations in (p,p`)-reactions, the double differential cross section and the spin-flip probability S{sub yy} are calculated for forward angles. They are in good agreement with experiments on 4{sup 0}Ca, {sup 48}Ca and {sup 208}Pb at intermediate incident energies (200 MeV - 800 MeV). The experimentally observed spin-dipole resonance in 4{sup 0}Ca can be reproduced. S{sub yy} depends sensitively on the distorions of the projectile wave. Different versions of the Nanti N-potential of the Bonn-Juelich group have been used to calculate (anti p,anti p`) cross sections on {sup 12}C. They show large sensitivity for unnatural parity states. Because of the strong absorption, this reaction is an
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Citation Formats
Unkelbach, W.
Hadronic spin excitations in finite fermion systems; Hadronische Spinanregungen in endlichen Fermionensystemen.
Germany: N. p.,
1991.
Web.
Unkelbach, W.
Hadronic spin excitations in finite fermion systems; Hadronische Spinanregungen in endlichen Fermionensystemen.
Germany.
Unkelbach, W.
1991.
"Hadronic spin excitations in finite fermion systems; Hadronische Spinanregungen in endlichen Fermionensystemen."
Germany.
@misc{etde_10114042,
title = {Hadronic spin excitations in finite fermion systems; Hadronische Spinanregungen in endlichen Fermionensystemen}
author = {Unkelbach, W}
abstractNote = {Hadronic spin-excitations in finite Fermi systems are investigated by studying inelastic proton- and antiproton-nucleus scattering in doubly magic nuclei ({sup 12}C, 4{sup 0}Ca, {sup 48}Ca, {sup 208}Pb). The Random-Phase-Approximation (RPA) and the Distorted-Wave-Born-Approximation (DWBA) are used to describe the nuclear structure and reaction respectively. The possibility of a low-energy octupole resonance (LEOR) in {sup 208}Pb, which exhausts a significant fraction of the energy weighted sum rule, is investigated. It is found that the sum-rule fraction of {proportional_to} 15% seen in (p,p`) reactions depends sensitively on the strength of the isovector projectile-target nucleus interaction. To study spin-excitations in (p,p`)-reactions, the double differential cross section and the spin-flip probability S{sub yy} are calculated for forward angles. They are in good agreement with experiments on 4{sup 0}Ca, {sup 48}Ca and {sup 208}Pb at intermediate incident energies (200 MeV - 800 MeV). The experimentally observed spin-dipole resonance in 4{sup 0}Ca can be reproduced. S{sub yy} depends sensitively on the distorions of the projectile wave. Different versions of the Nanti N-potential of the Bonn-Juelich group have been used to calculate (anti p,anti p`) cross sections on {sup 12}C. They show large sensitivity for unnatural parity states. Because of the strong absorption, this reaction is an excellent probe for the long-range one-pion exchange. (orig.). [Deutsch] Im Rahmen dieser Arbeit wurde die Anregung verschiedener kollektiver Zustaende doppelt magischer Kerne ({sup 12}C, 4{sup 0}Ca, {sup 48}Ca, {sup 208}Pb) durch inelastische Proton- und Antiproton-Kern-Steuerung untersucht. Dazu kam die RPA zur Darstellung der Kernstruktur und die DWBA fuer die Reaktionsrechnung zur Anwendung. Die Analyse von Wirkungsquerschnitten und Spinobservablen erlaubte Rueckschluesse auf die effektive Projektil-Target-Wechselwirkung sowie auf die Natur der betrachteten Anregungen. (orig.).}
place = {Germany}
year = {1991}
month = {May}
}
title = {Hadronic spin excitations in finite fermion systems; Hadronische Spinanregungen in endlichen Fermionensystemen}
author = {Unkelbach, W}
abstractNote = {Hadronic spin-excitations in finite Fermi systems are investigated by studying inelastic proton- and antiproton-nucleus scattering in doubly magic nuclei ({sup 12}C, 4{sup 0}Ca, {sup 48}Ca, {sup 208}Pb). The Random-Phase-Approximation (RPA) and the Distorted-Wave-Born-Approximation (DWBA) are used to describe the nuclear structure and reaction respectively. The possibility of a low-energy octupole resonance (LEOR) in {sup 208}Pb, which exhausts a significant fraction of the energy weighted sum rule, is investigated. It is found that the sum-rule fraction of {proportional_to} 15% seen in (p,p`) reactions depends sensitively on the strength of the isovector projectile-target nucleus interaction. To study spin-excitations in (p,p`)-reactions, the double differential cross section and the spin-flip probability S{sub yy} are calculated for forward angles. They are in good agreement with experiments on 4{sup 0}Ca, {sup 48}Ca and {sup 208}Pb at intermediate incident energies (200 MeV - 800 MeV). The experimentally observed spin-dipole resonance in 4{sup 0}Ca can be reproduced. S{sub yy} depends sensitively on the distorions of the projectile wave. Different versions of the Nanti N-potential of the Bonn-Juelich group have been used to calculate (anti p,anti p`) cross sections on {sup 12}C. They show large sensitivity for unnatural parity states. Because of the strong absorption, this reaction is an excellent probe for the long-range one-pion exchange. (orig.). [Deutsch] Im Rahmen dieser Arbeit wurde die Anregung verschiedener kollektiver Zustaende doppelt magischer Kerne ({sup 12}C, 4{sup 0}Ca, {sup 48}Ca, {sup 208}Pb) durch inelastische Proton- und Antiproton-Kern-Steuerung untersucht. Dazu kam die RPA zur Darstellung der Kernstruktur und die DWBA fuer die Reaktionsrechnung zur Anwendung. Die Analyse von Wirkungsquerschnitten und Spinobservablen erlaubte Rueckschluesse auf die effektive Projektil-Target-Wechselwirkung sowie auf die Natur der betrachteten Anregungen. (orig.).}
place = {Germany}
year = {1991}
month = {May}
}