Extended shell model calculation of the T=0 natural parity spectrum of 4He

Ceuleneer, R.; Vandepeutte, P.; Semay, Claude

doi:10.1016/0370-2693(87)90736-2

Cited by 20 publications

(17 citation statements)

References 12 publications

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“…The simplicity of our basis allowed us to include excitations of up to 6Ohw. much higher than similar (unconverged) shell-model calculations using an unrestricted basis [4,5], and we thus obtained significantly better ground-state energies. It was found that very large bases are in fact required, with convergence only being achieved for these two potentials at roughly the 40hw and 20hw level, respectively.…”

supporting

confidence: 40%

Combinatorial Fabrication Process for a-Si:H Thin Film Transistors

Aiyer

Nishioka

Maruyama

et al. 2001

Jpn. J. Appl. Phys.

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Absmct.A previous shell-model-style calculation for the ground-state energy of the 'He nucleus, based on coupled cluster techniques, was able to treat exactly the centre-of-mass motion. It is now recast in a precisely equivalent but vastly more computationally efiaent form, directly in terms of coordinate-space correlation functions which are expanded in a Gaussian geminal basis and determined variationally. This reformulation further leads in a straightforward manner to a natural procedure for including higher-order correlations. Its implementation at even the simplest level produces a significant improvement in the already very good upper bounds achieved far the ground-state energy. Further extensions are also discussed.

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supporting

confidence: 40%

Combinatorial Fabrication Process for a-Si:H Thin Film Transistors

Aiyer

Nishioka

Maruyama

et al. 2001

Jpn. J. Appl. Phys.

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“…For instance, the beta decay rate of tritium [3] is about 8% less than predicted by this model. Less directly, it has been shown that calculations of the binding energy of He require inclusion of excitations up to 10%co in order to reproduce the measured binding [11], and comparable excitations would be expected in A =3 nuclei as well. It has also been shown [12] that in Faddeev calculations of the binding energy of H up to 34 channels are required in order to achieve convergence.…”

Section: Data Analysis and Resultsmentioning

confidence: 91%

Search for Gamow-Teller strength in the continuum via theHe3(n,p)
Celler
¹
,
Yen
²
,
Alford
³

et al. 1993
Phys. Rev. C
8
0
1
0
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Cross sections for the He(n, p) reaction were measured at angles of 2.7 ', 7.5', 14.4', 28.2', and 34. 9' (c.m. ) at an incident beam energy of 288 MeV. Outgoing protons were observed to energies corresponding to a Q value of -40 MeV. The reduced cross section for the Gamow-Teller component of the ground-state isobaric-analog transition was determined to be & =o(q =0)/BGT =6.9+0.2 mb jsr. This value is significantly smaller than that observed for nuclei in the mass range 6~A~1 3. A multipole analysis of the data indicates that the cross section of the continuum up to a g value of -20 MeV involves mainly hL =1 spin dipole transitions. The analysis determines an upper limit of 0.06 units of Gamow-Teller strength in transitions to excited states between 7 and 16 MeV, but is consistent with no Gamow-Teller strength in this region. Distorted wave impulse approximation calculations using transition amplitudes from a large-scale shell model calculation provide a good fit to the measured groundstate cross section, but fail to account for the magnitude of the measured cross sections to the continuum below 30 MeV excitation.PACS number(s): 24.50.+ g, 25.40.Kv, 27.10.+h

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“…For example, at nmaz = 29, which corresp.onds to 581i.w excitation, the first method requires the computation of 30X30 matrix elements, whereas the QT ICC requires the calculation of 465 X 465 matrix elements. In any case, these numbers are still very much smaller than the dimensions corresponding to a full configuration interaction calculation [23]in the complete nmo.znw space.…”

Section: Value (Ii!ticcihiii!ticc)/(ii!ticclii!ticc)mentioning

confidence: 84%

“…The disadvantage of this approach is that many of the states which result after the diagonalization of the hamiItonian matrix are not physical, because they correspond to excitations of the centre-of-mass. Moreover, the dimension of the space grows very rapidly with Nmax [16,23].…”

Section: Introductionmentioning

confidence: 99%

Translationally-Invariant Coupled Cluster Theory Applied to the 4He Nucleus

Bishop¹,

Flynn²,

Boscá

et al. 1990

Condensed Matter Theories

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In this work we discuss a series of calculations for the 4 He nucleus which have been motivated by the coupled cluster method. For pedagogical reasons we restrict ourselves to the case of pure Wigner nucleon-nucleon interactions. All numerical work is done in the standard harmonic oscillator basis and with an exact treatment of the centre-of-mass motion. Particular emphasis is placed on elucidating the meaning of the coupled cluster wave function and its coordinate-space representation, as well as the relation with a variational-like use of the coupled cluster ansatz.

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Extended shell model calculation of the T=0 natural parity spectrum of 4He

Cited by 20 publications

References 12 publications

Combinatorial Fabrication Process for a-Si:H Thin Film Transistors

Combinatorial Fabrication Process for a-Si:H Thin Film Transistors

Search for Gamow-Teller strength in the continuum via theHe3(n,p)
Celler
¹
,
Yen
²
,
Alford
³

et al. 1993
Phys. Rev. C
8
0
1
0
View full text Add to dashboard Cite

Translationally-Invariant Coupled Cluster Theory Applied to the 4He Nucleus

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Extended shell model calculation of the T=0 natural parity spectrum of 4He

Cited by 20 publications

References 12 publications

Combinatorial Fabrication Process for a-Si:H Thin Film Transistors

Combinatorial Fabrication Process for a-Si:H Thin Film Transistors

Search for Gamow-Teller strength in the continuum via theHe3(n,p)Celler1, Yen2, Alford3 et al. 1993Phys. Rev. C8010View full textAdd to dashboardCite

Translationally-Invariant Coupled Cluster Theory Applied to the 4He Nucleus

Contact Info

Product

Resources

About

Search for Gamow-Teller strength in the continuum via theHe3(n,p)
Celler
¹
,
Yen
²
,
Alford
³

et al. 1993
Phys. Rev. C
8
0
1
0
View full text Add to dashboard Cite