Nucleon-Nucleus Collisions and Intermediate Structure

Mekjian, A. Z.

doi:10.1007/978-1-4615-9044-6_1

Cited by 7 publications

(6 citation statements)

References 171 publications

Supporting

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“…A change in sign should occur when the energies E r cross E f + . This is similar to the circumstances that occur in isobaric analog resonances [11,14].…”

supporting

confidence: 72%

“…r , Γ s.p. ≫ Γ d ≫ Γ r[11,14].These intermediate resonances are usually non-overlapping and their spacings D d are such that D s.p. ≫ D d > D r .…”

mentioning

confidence: 99%

“…and the compound width Γ r , Γ s.p. ≫ Γ d ≫ Γ r [11,14] Let us now use this information about the intermediate structure to consider some models for parity violation in these heavy nuclei. Let us first consider a model which connects to the observation of intermediate structure in the (n, f ) reaction.…”

mentioning

confidence: 99%

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Nearby Doorway States, Parity Doublets, and Parity Mixing in Compound Nuclear States

1995

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We discuss the implications of a doorway state model for parity mixing in compound nuclear states. We argue that in order to explain the tendency of parity violating asymmetries measured in 233 Th to have a common sign, doorways that contribute to parity mixing must be found in the same energy neighbourhood of the measured resonance. The mechanism of parity mixing in this case of nearby doorways is closely related to the intermediate structure observed in nuclear reactions in which compound states are excited. We note that in the region of interest ( 233 Th) nuclei exhibit octupole deformations which leads to the existence of nearby parity doublets. These parity doublets are then used as doorways in a model for parity mixing. The contribution of such mechanism is estimated in a simple model.

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“…A change in sign should occur when the energies E r cross E f + . This is similar to the circumstances that occur in isobaric analog resonances [11,14].…”

supporting

confidence: 72%

“…r , Γ s.p. ≫ Γ d ≫ Γ r[11,14].These intermediate resonances are usually non-overlapping and their spacings D d are such that D s.p. ≫ D d > D r .…”

mentioning

confidence: 99%

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Nearby Doorway States, Parity Doublets, and Parity Mixing in Compound Nuclear States

1995

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“…In that case questions of intermediate structure [14,31] in the nucleus become relevant. In a future publication we shall address this question.…”

Section: Discussion Of Results and Conclusionmentioning

confidence: 99%

Theory of parity violation in compound nuclear states: One particle aspects

Auerbach

Spevak

1994

Phys. Rev. C

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In this work we formulate the reaction theory of parity violation in compound nuclear states using Feshbach s projection operator formalism. We derive in this framework a complete set of terms that contribute to the longitudinal asymmetry measured in experiments with polarized epithermal neutrons. We also discuss the parity violating spreading width resulting from this formalism. We then use the above formalism to derive expressions which hold in the case when the doorway state approximation is introduced. In applying the theory we limit ourselves in this work to the case when the parity violating (PV) potential and the strong interaction are one body. In this approximation, using as the doorway the giant spin-dipole resonance and employing well-known optical potentials and a time-reversal even, parity odd one-body interaction we calculate or estimate the terms we derived. Among others, we evaluate numerically a new "direct" term and the channel coupling term first derived by Lewenkopf and Weidenmiiller, this in addition to the evaluation of the main "compound" term. In our calculations we explicitly orthogonalize the continuum and bound wave functions. We find the effects of orthogonalization to be very important. Our conclusion is that the present one-body theory cannot explain the average longitudinal asymmetry found in the recent polarized neutron experiments. We also confirm the discrepancy, first pointed out by Auerbach and Bowman, that emerges, between the calculated average asymmetry and the parity violating spreading width, when distant doorways are used in the theory.PACS number(s): 24.80. Dc, 24.60.Dr, 25.40. Ny, 24.10.i

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“…Event-by-event fluctuations on charged particle multiplicity and transverse momentum have been studied to understand the properties of QCD phase in heavy-ion collisions. Several candidates of order parameters in QCD phase, for example correlation length [ 1] and specific heat [ 2,3], can be extracted from these observables. It enables us to characterize the critical point of the phase transition by surveying the behavior of order parameters as a function of temperature or energy density of the system.…”

Section: Introductionmentioning

confidence: 99%