Stretched-state excitations with the (p,n) reaction at 135 MeV on [sup 14]C, [sup 18]O and [sup 30]Si

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1992

OSTI ID:7233211

Garcia, L A

Neutron time-of-flight spectra were obtained for the [sup 14]C(p,n)[sup 14]N, [sup 18]O(p,n)[sup 18]F, and [sup 30]Si(p,n)[sup 30]P reactions at 135 MeV with the beam-swinger system at the Indiana University Cyclotron Facility. Excitation-energy spectra and the differential cross sections for the observed excitations in these reactions were extracted over the momentum transfer range from 0 to 2.7 fm[sup [minus]1]. The goal of this work was to obtain the strengths and distributions for the stretched states. The identification of these states was based on comparisons of the theoretical differential cross sections, performed in a DWIA formalism, with the experimental cross sections. Isospin assignments were based on comparison of the measured (p,n) and (e,e[prime]) spectroscopic strengths. Candidate ([pi]d[sub 5/2],[nu]p[sub 3/2][sup [minus]1]), J[sup pi] = 4[sup [minus]] T = 0, 1 and 2, 1[h bar][omega] states, were identified at E[sub x] = 8.5, 13.8, 19.5, and 26.7 MeV in the [sup 14]C(p,n)[sup 14]N reaction, and the isovector strengths were extracted. In the [sup 18]O(p,n)[sup 18]F reaction at 135 MeV, ([pi]d[sub 5/2],[nu]d[sub 5/2][sup [minus]1])5[sup +] T = 0 O[h bar][omega] strength was observed, concentrated in a single state, at E[sub x] = 1.1 MeV. Candidate ([pi]d[sub 5/2],[nu]p[sub 3/2][sup [minus]1]) J[sup [pi]] = 4[sup [minus]] T = 0, 1 and 2, 1[h bar][omega] states, were identified at E[sub x] = 3.9, 9.4, 10.2, 11.4, 12.0, 14.4, 15.3, 17.3, 18.0, 19.7, 21.4, and 23.4 MeV. In the [sup 30]Si(p,n)[sup 30]P reaction at 135 MeV, candidate ([pi]f[sub 7/2],[nu]d[sub 5/2][sup [minus]1]) J[pi] = 6[sup [minus]] T = 0, 1 and possible 2, 1 [h bar][omega] states, were identified at E[sub x] = 5.8, 6.4, 7.2, 7.7, 8.9, 10.2, 11.3, 13.5, and 17.4 MeV. Preliminary (e,e[prime]) results are in poor agreement with the (p,n) results. One candidate ([pi]d[sub 5/2],[nu]d[sub 5/2][sup [minus]1]) J[sup pi] = 5[sup +] 0[h bar][omega] state was identified at E[sub x] = 4.3 MeV.

• Research Organization: Kent State Univ., OH (United States)
• OSTI ID: 7233211
• Country of Publication: United States
• Language: English

Related Subjects

663430* -- Nucleon-Induced Reactions & Scattering-- (1992-)
663520 -- Nuclear Mass Ranges-- A=6-19-- (1992-)
663530 -- Nuclear Mass Ranges-- A=20-38-- (1992-)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ACCELERATORS
BARYON-BARYON INTERACTIONS
CARBON 14 TARGET
CROSS SECTIONS
CYCLIC ACCELERATORS
CYCLOTRONS
DIFFERENTIAL CROSS SECTIONS
ENERGY LEVELS
ENERGY RANGE
ENERGY SPECTRA
EXCITED STATES
HADRON-HADRON INTERACTIONS
INTERACTIONS
ISOCHRONOUS CYCLOTRONS
IU CYCLOTRON
MATHEMATICAL MODELS
MEV RANGE
MEV RANGE 100-1000
NUCLEAR MODELS
NUCLEON-NUCLEON INTERACTIONS
OXYGEN 18 TARGET
PARTICLE INTERACTIONS
PROTON-NEUTRON INTERACTIONS
PROTON-NUCLEON INTERACTIONS
SHELL MODELS
SILICON 30 TARGET
SPECTRA
TARGETS
TIME-OF-FLIGHT METHOD