scholarly journals Study of the Generalized Momentum Distribution of Model Nuclear Matter

2020 ◽  
Vol 5 ◽  
pp. 139
Author(s):  
E. Mavrommatis ◽  
M. Petraki ◽  
J. W. Clark

Valuable information on the correlation structure of the nuclear medium is stored in the generalized momentum distribution n(p,Q), the Fourier transform of the half-diagonal two-body density matrix ρ_{2η}(r_1,r_2,r'). In this paper, we present a numerical calculation of n(p,Q) for two Jastrow-correlated models of symmetrical nuclear matter based on the structural decomposition of n(p,Q) derived by Ristig and Clark and on a Fermi-hypernetted-chain procedure. Results exhibit significant departures from the ideal Fermi gas case in certain kinematic domains; this behaviour indicates the strong short-range correlations present in these models. Nevertheless, such deviations are less prominent than in earlier low- cluster-order calculations. The results are also used to judge the quality of Silver's approximation for n(p,Q).

2020 ◽  
Vol 6 ◽  
pp. 58
Author(s):  
M. Petraki ◽  
E. Mavrommatis ◽  
J. W. Clark

The half-diagonal two-body density matrix ρ_{2h}/i(r1,r2,r') plays a central role in most theoretical treatments of the propagation of ejected nucléons and their final state interactions (FSI) in the nuclear medium. In this work based on the analysis of Ristig and Clark, we present the results of a Fermi hypernetted-chain calculation ρ_{2h}/i(r1,r2,r') for infinite symmetrical nuclear matter using a Jastrow-correlated model. The dependence of ρ_{2h} on the variables involved has been investigated in detail. Significant departures from ideal Fermi gas behavior in certain domains demonstrate the importance of short-range correlations. A comparison of our results with the predictions of Silver's approximation to ρ_{2h}, which has been employed in some treatments of FSI, reveals certain shortcomings of this approximation. The Fermi hypernetted-chain results obtained here will serve as a key input to an approximate treatment of FSI in inclusive quasielastic electron scattering from nuclear matter.


2019 ◽  
Vol 3 ◽  
pp. 88
Author(s):  
E. Mavromanatis ◽  
Μ. Petraki ◽  
J. W. Clark

A lowest-cluster-order variational calculation of the half-diagonal two-body density matrix ρ2(r1,r2,r’1) and the corresponding generalized momentum distribution n(p.Q) is performed for three representative models of nuclear matter containing central correlations. Dynamical correlations produce significant deviations from the results for a noninteracting Fermi gas. Calculations axe in progress that include higherorder cluster corrections as well as state-dependent correlations


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.


2012 ◽  
Vol 21 (12) ◽  
pp. 1250095 ◽  
Author(s):  
M. AJAZ ◽  
M. K. SULEYMANOV ◽  
K. H. KHAN ◽  
A. ZAMAN

The present work reports the use of nuclear transparency effect of protons in proton– and deuteron–carbon interactions at 4.2A GeV /c to get information about the states of nuclear matter. The "half-angle" technique is used to extract the information on nuclear transparency. The results are compared with Dubna version of Cascade model. The average values of multiplicity, momentum and transverse momentum of protons are analyzed as a function of the number of identified protons in an event. We observed some evidence and trends in the data, which could be considered as transparency effect. Analysis of the results shows that the leading effect is the basis of the observed transparency. Some contribution to the observed effect could be the existing short range correlations and the scaling power law s-N, for exclusive two-body hard scattering.


1986 ◽  
Vol 451 (2) ◽  
pp. 243-268 ◽  
Author(s):  
K. Nakayama ◽  
S. Krewald ◽  
J. Speth

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