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Danilin, A. A.; Пурыгин, П. П.; Макарова, Н. В.; Земцова, М. Н.; Моисеев, И. К.

doi:10.1023/a:1012321316491

Cited by 5 publications

(4 citation statements)

References 6 publications

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“…The fragment spectra from studied direct decays reflect the three-body nuclear structure. For example, the α+N+N correlations in A=6 nuclei calculated in [7][8][9] (the fragment correlations both in space and in involved angular momenta) agree quantitatively with the conclusions of data analysis. In particular, the strong momentum and space correlations between two valence protons are found in 6 Be.…”

Section: Expansion Of a Decay Amplitude Into A Series Of K-harmonicssupporting

confidence: 62%

Two-proton emission in the hyperharmonics approach

Mukha

2000

AIP Conference Proceedings

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Nuclear decays into three-particle channels are considered in a few-body approach of hyperspherical harmonics with emphasis on simultaneous, or direct, emission of two protons. General conditions of direct decays are described and their main features, being experimentally established in decays of light nuclei, are reported.The analysis method based on an expansion of decay amplitude into a series of hyperspherical harmonics is reviewed. The basis of hyperspherical harmonics functions is a generalisation of the spherical function basis in three-body systems. The method is tested on analysis of the direct decay 6 Be→ α+p+p where the three-body components in the nuclear structure of 6 Be have been studied. In particular, the observed strong protonproton correlations are treated as a manifestation of a specific three-body quantum effect: the kinematic focusing of fragments over momenta and in space.The hyperspherical harmonics method is applied for the predictions of proton-proton correlations and life-time estimates of the nuclei 19 Mg, 34 Ca and 48 Ni -candidates for two-proton radioactivity. Each direct 2p-decay should result in a set of peaks in the E p−p spectrum whose number and positions depend on the structure of initial nucleus, opposite to the diproton model, predicting the 2 He emission with one peak at E p−p ≈0 in all cases.

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Section: Expansion Of a Decay Amplitude Into A Series Of K-harmonicssupporting

confidence: 62%

Two-proton emission in the hyperharmonics approach

Mukha

2000

AIP Conference Proceedings

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“…The influence of the initial-state structure and the reaction mechanism on three-body decays is investigated by example of the 6 Be continuum populated in neutron-knockout reactions on 7 Be. The sensitivity of the 6 Be excitation spectrum and the three-body correlations to the different components of the model is demonstrated.…”

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confidence: 99%

“…(2) and thus is not present in Eq. (7). The fivedimensional "hyperspherical solid angle" Ω 5 includes two degrees of freedom describing the "internal correlations" of the three-body system which are ordinarily considered as being completely defined by the dynamics of the threebody motion itself.…”

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confidence: 99%

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Sensitivity of three-body decays to the reactions mechanism and the initial structure by example of6Be

Grigorenko

Егорова²,

Charity

et al. 2012

Phys. Rev. C

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The influence of the initial-state structure and the reaction mechanism on three-body decays is investigated using the example of the 6 Be continuum populated in neutron-knockout reactions on 7 Be. The sensitivity of the 6 Be excitation spectrum and the three-body correlations to the different components of the model is demonstrated. It is shown that the spin composition of the initial state may have an overwhelming effect on the three-body continuum. The characteristics and structure of the second 0 + 2 and 2 + 2 states in 6 Be are predicted and the conditions for their reliable observations are formulated. The effects of interference and the alignment of three-body states on the three-body correlations are demonstrated.Introduction. The study of systems beyond nuclear driplines is an important trend in modern low-energy nuclear research. Many of these systems belong to the three-body or even few-body continuum, and the reaction theory for populating these states is not well developed. Modern high-precision experiments with exotic beams require complicated analyses and advanced theoretical treatment, and call for deeper insights in this field.Observables in reactions producing unbound systems depend on three major ingredients: (i) the structure of initial nuclei, (ii) the reaction mechanism, and (iii) the final-state interaction (FSI). For very narrow resonances (extremely long-lived states), the aspects (i) and (ii) lose importance as the structure formed in the reaction has enough time to "forget" how it was created. Then for a consistent description of the system, it is sufficient to study only the decay process (FSI effects) by itself. However, exactly when this approach becomes valid is not always clear in advance. Clarity in this issue is especially important for systems beyond the driplines, where the resonant states (often already the ground states) are quite broad.In this work, we demonstrate the importance of the reaction mechanism and the initial-state structure for investigations of few-body systems beyond the driplines using the example of 6 Be (three-body α + p + p continuum) populated in neutronknockout reactions from 7 Be projectiles. The first result of these studies has been published in Ref.[1], elucidating the mechanism of democratic decay. Good agreement with experimental data was demonstrated for both the excitation spectrum and the three-body energy-angular correlations over a broad range of excitation energy. However, in this compact experimental work, many important theoretical issues of broader interest were left aside. In the present work, we focus on the most interesting theoretical results arising from our studies of the data [1]. This is a timely message considering the recent interest in the 6 Be system [2-6]. We also think that these

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