[Delta] excitations in nuclei and their decay properties

Journal Article · Wed Jun 01 04:00:00 EDT 1994 · Physical Review, C (Nuclear Physics); (United States)

DOI:https://doi.org/10.1103/PhysRevC.49.3162· OSTI ID:7116793

Udagawa, T ^[1]; Oltmanns, P; Osterfeld, F ^[2]; Hong, S W ^[3]

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1. Department of Physics, University of Texas, Austin, Texas 78712 (United States)
2. Institut fuer Kernphysik, KFA Juelich GmbH, 52455 Juelich (Germany)
3. Sung Kyun Kwan University, Suwon, 440-746 (Korea, Republic of)

A formalism for the calculation of intermediate energy charge exchange reactions exciting the [Delta] resonance region in nuclei is presented. The nuclear structure part of the formalism is based on the isobar-hole model and the nuclear reaction part is treated within the distorted-wave impulse approximation (DWIA). In the nuclear structure part, all important nuclear medium effects are included, such as nucleon and isobar binding, two-body [Delta] isobar-nucleon hole correlations, and intermediate coupling to multiparticle-multihole channels. The latter coupling is treated phenomenologically through a [Delta] spreading potential. Explicit account is also taken of the nucleon knockout mode and the related nucleon particle-nucleon hole correlations. In order to perform the calculations, we first set up coupled-channel equations for the excited nucleon and [Delta], which are slightly, but importantly, transformed into equations for localized functions only. We solve these equations by using the Lanczos method. The resultant formalism allows us to calculate cross sections for [Delta] excitation, quasielastic scattering, and low-lying Gamow-Teller excitations on the same footing. In this way a detailed study of the nuclear medium effects on the [Delta] isobar can be done. Particular attention is paid to the [Delta]-hole correlations in the spin-longitudinal ([bold S][center dot][bold q][bold T]) channel. It is shown that the coherent pion production events in the exclusive [sup 12]C([ital p],[ital n][pi][sup +])[sup 12]C(g.s.) and [sup 12]C([sup 3]He,[ital t][pi][sup +])[sup 12]C(g.s.) reactions provide a unique signature on the nuclear pionic mode.

• DOE Contract Number: FG03-93ER40785
• OSTI ID: 7116793
• Journal Information: Physical Review, C (Nuclear Physics); (United States), Journal Name: Physical Review, C (Nuclear Physics); (United States) Vol. 49:6; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

662410 -- Properties of Baryons & Baryon Resonances-- (1992-)
663110 -- General & Average Properties of Nuclei & Nuclear Energy Levels-- (1992-)
663300* -- Nuclear Reactions & Scattering
General-- (1992-)
663520 -- Nuclear Mass Ranges-- A=6-19-- (1992-)
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BARYON REACTIONS
BARYONS
CARBON 12 TARGET
CHARGE-EXCHANGE REACTIONS
CHARGED-PARTICLE REACTIONS
COLLECTIVE EXCITATIONS
CORRELATIONS
COUPLED CHANNEL THEORY
CROSS SECTIONS
DECAY
DELTA BARYONS
DIRECT REACTIONS
DISTORTED WAVE THEORY
ELEMENTARY PARTICLES
ENERGY RANGE
ENERGY-LEVEL TRANSITIONS
EXCITATION
FERMIONS
HADRON REACTIONS
HADRONS
HELIUM 3 REACTIONS
IMPULSE APPROXIMATION
ISOBAR MODEL
MATHEMATICAL MODELS
MEV RANGE
MEV RANGE 100-1000
N BARYONS
NUCLEAR REACTIONS
NUCLEAR STRUCTURE
NUCLEI
NUCLEON REACTIONS
PARTICLE MODELS
PROTON REACTIONS
QUASI-ELASTIC SCATTERING
QUASI-FREE REACTIONS
RESONANCE
SCATTERING
TARGETS