Photopion production in the Fermi-gas model

MacDonald, William M.; Dressler, Edward T.; O'Connell, J.S.

doi:10.1103/physrevc.19.455

Cited by 11 publications

(6 citation statements)

References 6 publications

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“…[28,41] in the case of pion photoproduction, Fermi motion can be approximated by choosing κ = 1. This approximation can reproduce the exact cross section to within an accuracy of 7% [42]. Figure 7 compares the cross sections calculated in the two approximations with the exact calculation.…”

Section: Resultsmentioning

confidence: 87%

Electromagnetic production of the hypertriton

Mart¹,

Tiator²,

Drechsel³

et al. 1998

Nuclear Physics A

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Kaon photoproduction on 3 He, γ + 3 He −→ K + + 3 Λ H, is studied in the framework of the impulse approximation. Realistic 3 He wave functions obtained as solutions of Faddeev equations with the Reid soft-core potential are used along with different 3 Λ H wave functions. Results are compared for several elementary operator models, which can successfully describe the elementary kaon production off the proton up to a photon lab energy of k = 2.2 GeV. It is found that the corresponding cross sections are small, of the order of several nanobarns. It is also shown that the influence of Fermi motion is important, while the effect of different off-shell assumptions on the cross section is not too significant. PACS number(s) : 13.60.Le, 25.20.Lj, 21.80.+a

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Section: Resultsmentioning

confidence: 87%

Electromagnetic production of the hypertriton

Mart¹,

Tiator²,

Drechsel³

et al. 1998

Nuclear Physics A

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“…From this study we have predicted the existence of a quenching of 17% of the nucleon polarizability in the nuclear medium due to the Pauli blocking effects. This has been investigated by McDonald et al [20]. It is nevertheless detectable using dispersion relations for the real part of the forward Compton amplitude.…”

Section: Resultsmentioning

confidence: 95%

“…The quantity ~u is given by the dispersive integral c~:v=~ ~ ~f-aco (20) where aN(co) is the total nucleon photoabsorption cross section. The isobar is expected to affect mostly the magnetic polarizability.…”

Section: The Photon Scattering Amplitudementioning

confidence: 99%

Photonuclear reactions and dispersion relations

Rosa-Clot

Ericson

1985

Z Physik A

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We study the photonuclear reaction in the intermediate region. We evaluate the real part of the forward Compton amplitude through the dispersion relation and analyze its structure. The modification of the electromagnetic polarizability of the nucleon, ~, in the nuclear medium is calculated. We show that it affects appreciably the behaviour of the Compton amplitude in the intermediate region, consistent with the experimental data. In the same scheme the enhancement of the photonuclear sum rule, K, is interpreted as an exchange contribution to the nucleon Compton amplitude. We find in lead a value of K = 1.6 +0.2 and a quenching of about 20 % of ~.

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“…However this is not possible because the Pauli blocking itself is aected by the existence of the . It is indeed known that the modication of the pion propagation in the nuclear medium, due to the virtual -hole excitations, makes the Pauli blocking less eective [7]. It is thus not possible to disentangle the in the pion photoproduction region.…”

Section: Dispersion Relations and Compton Amplitudementioning

confidence: 99%

Chiral restoration and the extended photoabsorption sum rule in nuclei

Ericson

Rosa-Clot

Kulagin

1998

Il Nuovo Cimento A (1971-1996)

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The Bethe{Levinger sum rule is extended beyond the potential model. The pion degrees of freedom are taken into account and the modications of the potential theory are analysed within two dierent approaches: dipole sum rule and dispersion relation on the Compton amplitude.Our aim is to extract from the photon data experimental information on the expectation value of the square of the pion eld, a quantity which e n ters also in the restoration of chiral symmetry in nuclei and in pion{nucleus scattering. We are led to incorporate in the description the resonance, which is strongly excited by the pion degrees of freedom.

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Photopion production in the Fermi-gas model

Cited by 11 publications

References 6 publications

Electromagnetic production of the hypertriton

Electromagnetic production of the hypertriton

Photonuclear reactions and dispersion relations

Chiral restoration and the extended photoabsorption sum rule in nuclei

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