Elastic scattering of polarized protons from nuclei near A = 200 between 11 and 14 MeV

Rathmell, R.D.; Haeberli, W.

doi:10.1016/0375-9474(72)90473-3

Cited by 25 publications

(3 citation statements)

References 15 publications

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“…The single-particle widths r s#p< (m) are calculated from scattering in a real potential well, with parameters determined from elastic scattering data. 6 The amplitudes a mi we calculate in a Tamm-Dancoff (TD) approximation with a particle-hole interaction g 0 ' d 1 • a 2 Tj_ • r 2 6(x 1 -r 2 ). If we adjust g 0 ' to reproduce the GT resonance energy we find g 0 r = 245 MeV fm 3 and the particle-hole amplitudes as given in Table I.…”

mentioning

confidence: 99%

Decay of the Giant Gamow-Teller Resonance inBi208

et al. 1981

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mentioning

confidence: 99%

Decay of the Giant Gamow-Teller Resonance inBi208

et al. 1981

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“…5, elastic scattering cross-sections dσ p+Au dΩ (θ M ), were calculated using FRESCO [30] with optical potentials from refs. [31,32]. For both potentials, the proton elastic scattering crosssection at 33.9 • (the angle selected for normalization of the 12 C(p, p ) data) deviated by < 1% from the Rutherford scattering formula at these energies, making the choice of potential insignificant to the overall normalization of the p+ 12 C cross-sections.…”

Section: Discussionmentioning

confidence: 95%

High precision proton angular distribution measurements of $^{12}$C(p,p') for determination of the $E0$ decay branching ratio of the Hoyle state

Cook,

Chevis,

Eriksen

et al. 2022

Preprint

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Background In stellar environments, carbon is produced exclusively via the 3α process, where three α particles fuse to form 12 C in the excited Hoyle state, which can then decay to the ground state. The rate of carbon production in stars depends on the radiative width of the Hoyle state. While not directly measurable, the radiative width can be deduced by combining three separately measured quantities, one of which is the E0 decay branching ratio. The E0 branching ratio can be measured by exciting the Hoyle state in the 12 C(p, p ) reaction and measuring the pair decay of both the Hoyle state and the first 2 + state of 12 C.Purpose To reduce the uncertainties in the carbon production rate in the universe by measuring a set of proton angular distributions for the population of the Hoyle state (0 + 2 ) and 2 + 1 state in 12 C in 12 C(p, p ) reactions between 10.20 and 10.70 MeV, used in the determination of the E0 branching ratio of the Hoyle state.Method Proton angular distributions populating the ground, first 2 + , and the Hoyle states in 12 C were measured in 12 C(p,p') reactions with a silicon detector array covering 22 • < θ < 158 • in 14 small energy steps between 10.20 and 10.70 MeV with a thin (60 µg/cm 2 ) nat C target.Results Total cross-sections for each state were extracted and the population ratio between the 2 + 1 and Hoyle state determined at each energy step. By appropriately averaging these cross-sections and taking their ratio, the equivalent population ratio can be extracted applicable for any thick 12 C target that may be used in pair-conversion measurements. This equivalent ratio agreed with a direct measurement performed with a thick target.Conclusions We present a general data set of high-precision 12 C(p, p ) cross-sections that make uncertainties resulting from the population of the 2 + 1 and 0 + 2 states by proton inelastic scattering negligible for any future measurements of the E0 branching ratio in 12 C. Implications for future measurements are discussed, as well as possible applications of this data set for investigating cluster structures in 13 N.

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“…( 5), elastic scattering cross sections dσ p+Au d (θ M ) were calculated using FRESCO [30] with optical potentials from Refs. [31,32]. For both potentials, the proton elastic scattering cross-section at 33.9 • (the angle se-FIG.…”

Section: Discussionmentioning

confidence: 99%

High-precision proton angular distribution measurements of C12(p,p′) for the determination of the
Cook
¹
,
Chevis
²
,
Simpson
³

et al. 2021
Phys. Rev. C
4
0
4
0
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Background: In stellar environments, carbon is produced exclusively via the 3α process, where three α particles fuse to form 12 C in the excited Hoyle state, which can then decay to the ground state. The rate of carbon production in stars depends on the radiative width of the Hoyle state. While not directly measurable, the radiative width can be deduced by combining three separately measured quantities, one of which is the E 0 decay branching ratio. The E 0 branching ratio can be measured by exciting the Hoyle state in the 12 C(p, p ) reaction and measuring the pair decay of both the Hoyle state and the first 2 + state of 12 C. Purpose: We aim to reduce the uncertainties in the carbon production rate in the universe by measuring a set of proton angular distributions for the population of the Hoyle state (0 + 2 ) and 2 + 1 state in 12 C in 12 C(p, p ) reactions between 10.20 and 10.70 MeV, used in the determination of the E 0 branching ratio of the Hoyle state. Method: Proton angular distributions populating the ground, first 2 + , and the Hoyle states in 12 C were measured in 12 C(p, p ) reactions with a silicon detector array covering 22 • < θ < 158 • in 14 small energy steps between 10.20 and 10.70 MeV with a thin (60 μg/cm 2 ) nat C target. Results: Total cross sections for each state were extracted and the population ratio between the 2 + 1 and Hoyle state determined at each energy step. By appropriately averaging these cross sections and taking xtheir ratio, the equivalent population ratio can be extracted applicable for any thick 12 C target that may be used in pairconversion measurements. This equivalent ratio agreed with a direct measurement performed with a thick target. Conclusions: We present a general data set of high-precision 12 C(p, p ) cross sections that make uncertainties resulting from the population of the 2 + 1 and 0 + 2 states by proton inelastic scattering negligible for any future measurements of the E 0 branching ratio in 12 C. Implications for future measurements are discussed, as well as possible applications of this data set for investigating cluster structures in 13 N.

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Elastic scattering of polarized protons from nuclei near A = 200 between 11 and 14 MeV

Cited by 25 publications

References 15 publications

Decay of the Giant Gamow-Teller Resonance inBi208

Decay of the Giant Gamow-Teller Resonance inBi208

High precision proton angular distribution measurements of $^{12}$C(p,p') for determination of the $E0$ decay branching ratio of the Hoyle state

High-precision proton angular distribution measurements of C12(p,p′) for the determination of the
Cook
¹
,
Chevis
²
,
Simpson
³

et al. 2021
Phys. Rev. C
4
0
4
0
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Elastic scattering of polarized protons from nuclei near A = 200 between 11 and 14 MeV

Cited by 25 publications

References 15 publications

Decay of the Giant Gamow-Teller Resonance inBi208

Decay of the Giant Gamow-Teller Resonance inBi208

High precision proton angular distribution measurements of $^{12}$C(p,p') for determination of the $E0$ decay branching ratio of the Hoyle state

High-precision proton angular distribution measurements of C12(p,p′) for the determination of the Cook1, Chevis2, Simpson3 et al. 2021Phys. Rev. C4040View full textAdd to dashboardCite

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High-precision proton angular distribution measurements of C12(p,p′) for the determination of the
Cook
¹
,
Chevis
²
,
Simpson
³

et al. 2021
Phys. Rev. C
4
0
4
0
View full text Add to dashboard Cite