NUCLEAR MATTER AND THE LONG-RANGE PART OF THE NUCLEON–NUCLEON POTENTIAL

1967 ◽  
Vol 45 (3) ◽  
pp. 1289-1295 ◽  
Author(s):  
J. M. Pearson

Elementary nuclear-matter calculations are performed with five different central nucleon–nucleon potentials. These are all static with a hard core of radius 0.4 fm and an OPEP tail, but are characterized by vastly different forms in the intermediate region. It is concluded that nuclear matter is insensitive to the precise form of the central part of the nucleon–nucleon potential everywhere beyond the short-range repulsive region, provided the nucleon–nucleon data are well fitted.

1968 ◽  
Vol 46 (8) ◽  
pp. 963-969 ◽  
Author(s):  
Pierre Desgrolard ◽  
J. M. Pearson ◽  
Gérard Saunier

Tabakin and Davies have shown that it is possible to fit the singlet-state nucleon–nucleon data with a potential that is smooth enough to give very small second-order terms in an ordinary perturbation–theoretic treatment of nuclear matter. However, their potential is unrealistic in that the requirements of meson theory are in no way satisfied in the long-range region. It is shown here that a potential whose long-range part conforms to the OBEP of Bryan and Scott can still be made to fit the phase shifts without increasing significantly the second-order terms. Thus, with meson theory being incapable of making an unequivocal statement about the short-range region, it will only be by resorting to the experimental evidence for short-range correlations in nuclei that one will be able to resolve the question as to whether or not an interaction as smooth as the one considered here can be regarded as "real" rather than merely "effective". In any event, the existence of such correlations cannot be inferred from the singlet nucleon–nucleon data.


1969 ◽  
Vol 47 (24) ◽  
pp. 2825-2834 ◽  
Author(s):  
J. Law ◽  
R. K. Bhaduri

We have calculated the binding energies of 4He and 3H with soft- and hard-core nucleon–nucleon potentials. With central forces, using harmonic-oscillator wave functions, we find that accurate results can be obtained by taking only the long-range part of the potential and its second-order perturbative term. When tensor forces are present, the long-range interference term is also included in the calculation. In this case, the method is not accurate and underbinds these nuclei by about 1 MeV per particle. Ignoring Coulomb forces, our method yields a value of 18.5 MeV for the binding energy of 4He with the Hamada–Johnston potential.


1964 ◽  
Vol 42 (4) ◽  
pp. 696-719 ◽  
Author(s):  
R. K. Bhaduri ◽  
M. A. Preston

Recently, nonsingular velocity-dependent potentials have been constructed which fit the the two-nucleon data, but do not give saturation in nuclear matter at reasonable densities. In this paper, we have asked what features a potential should have in order to give saturation, and we have found that the short-range wave-function distortion (defined in the text) is important. Reasons are given for the failure of the earlier potentials to saturate, and a new velocity-dependent potential is proposed which gives results similar to the standard hard-core potential model. We speculate on the usefulness of such potentials for future calculations of nuclear properties.


1972 ◽  
Vol 5 (3) ◽  
pp. 911-913 ◽  
Author(s):  
S. Bhattacharyya ◽  
M. K. Roy

1986 ◽  
Vol 33 (2) ◽  
pp. 717-724 ◽  
Author(s):  
T. T. S. Kuo ◽  
Z. Y. Ma ◽  
R. Vinh Mau

2019 ◽  
Vol 34 (39) ◽  
pp. 1950322
Author(s):  
Marcello Baldo ◽  
Zahra Asadi Aghbolaghi ◽  
Isaac Vidaña ◽  
Mohsen Bigdeli

It has been found in previous works [M. Baldo and K. Fukukawa, Phys. Rev. Lett. 113, 241501 (2014); K. Fukukawa, M. Baldo, G. F. Burgio, L. Lo Monaco and H.-J. Schulze, Phys. Rev. 92, 065802 (2015)] that the nucleon–nucleon potential of [Y. Fujiwara, M. Kohno, C. Nakamoto and Y. Suzuki Phys. Rev. C 64, 054001 (2001); Y. Fujiwara et al., Phys. Rev. C 65, 014002 (2001)] gives an accurate saturation point in symmetric nuclear matter once the three hole-line contributions are included in the Brueckner–Bethe–Goldstone expansion without the addition of three-body forces in the nuclear Hamiltonian. The potential is based on a quark model of nucleons and on the quark–quark interaction together with quark exchange processes. These features introduce an intrinsic nonlocality of the nucleon–nucleon interaction. In order to clarify the role of the quark degrees of freedom and of the nonlocality in the saturation, we perform a comparative study of this potential and the traditional meson exchange models, exemplified in the CD-Bonn potential. We find that at the Brueckner–Hartree–Fock approximation, which corresponds to the two hole-line level of approximation, the dominant modification of the nucleon–nucleon interaction with respect to CD-Bonn is incorporated in the s-wave channels, where the quark degrees of freedom should be more relevant, in particular for the short range quark exchange processes. However, when the three hole-line contribution is included, we find that the higher partial waves play a relevant role, mainly in the term that describes the effect of the medium on the off-shell propagation of the nucleon.


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