Self-consistent description of long-range and short-range correlations in the theory of liquid He4. I

A scattering process can be a natural process or a process carried out in a laboratory. The scattering of particles from targets has resulted in important discoveries in physics. We discuss various scattering theories of electrons and positrons and their applications to elastic scattering, resonances, photoabsorption, excitation, and solar and stellar atmospheres. Among the most commonly employed approaches are the Kohn variational principle, close-coupling approximation, method of polarized orbitals, R-matrix formulation, and hybrid theory. In every formulation, an attempt is made to include exchange, long-range and short-range correlations, and to make the approach variationally correct. The present formulation, namely, hybrid theory, which is discussed in greater detail compared to other approximations, includes exchange, long-range correlations, and short-range correlations at the same time, and is variationally correct. It was applied to calculate the phase shifts for elastic scattering, the resonance parameters of two-electron systems, photoabsorption in two-electron systems, excitation of atomic hydrogen by an electron and positron impact, and to study the opacity of the Sun’s atmosphere. Calculations of polarizabilities, Rydberg states, and bound states of atoms are also discussed.

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Smooth nucleon–nucleon interactions and meson theory

Canadian Journal of Physics ◽

10.1139/p68-123 ◽

1968 ◽

Vol 46 (8) ◽

pp. 963-969 ◽

Cited By ~ 2

Author(s):

Pierre Desgrolard ◽

J. M. Pearson ◽

Gérard Saunier

Keyword(s):

Nuclear Matter ◽

Long Range ◽

Short Range ◽

Singlet State ◽

Nucleon Nucleon ◽

Second Order ◽

Meson Theory ◽

The One ◽

Range Part ◽

Short Range Correlations

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.

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LONG-RANGE FRACTAL CORRELATIONS IN LITERARY CORPORA

Fractals ◽

10.1142/s0218348x02001257 ◽

2002 ◽

Vol 10 (04) ◽

pp. 451-461 ◽

Cited By ~ 59

Author(s):

MARCELO A. MONTEMURRO ◽

PEDRO A. PURY

Keyword(s):

Long Range ◽

Short Range ◽

Fractal Structure ◽

Written Language ◽

Long Range Correlations ◽

Large Samples ◽

Sentence Level ◽

Set Up ◽

Short Range Correlations ◽

Linguistic Basis

In this paper, we analyze the fractal structure of long human language records by mapping large samples of texts onto time series. The particular mapping set up in this work is inspired on linguistic basis in the sense that is retains the word as the fundamental unit of communication. The results confirm that beyond the short-range correlations resulting from syntactic rules acting at sentence level, long-range structures emerge in large written language samples that give rise to long-range correlations in the use of words.

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Long-Range Ordered Phases without Short-Range Correlations

Physical Review Letters ◽

10.1103/physrevlett.61.1493 ◽

1988 ◽

Vol 61 (13) ◽

pp. 1493-1496 ◽

Cited By ~ 18

Author(s):

V. K. Kabra ◽

Dhananjai Pandey

Keyword(s):

Long Range ◽

Short Range ◽

Ordered Phases ◽

Short Range Correlations

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Basic features of correlated ion stopping in plasmas

Laser and Particle Beams ◽

10.1017/s0263034600010442 ◽

1996 ◽

Vol 14 (4) ◽

pp. 749-763 ◽

Cited By ~ 9

Author(s):

Günter Zwicknagel ◽

Claude Deutsch

Keyword(s):

Long Range ◽

Correlation Length ◽

Short Range ◽

Single Individual ◽

Screening Length ◽

Long Range Correlations ◽

Ion Clusters ◽

Large Ratio ◽

Basic Features ◽

Short Range Correlations

We reconsider correlated ion stopping in plasmas with the aim to emphasize the basic features and their underlying physics. For a better understanding of the effects connected with correlated ion stopping, it is useful to distinguish two types of correlated ion stopping, characterized by a small or large ratio of the correlation length of the ions to the screening length in the plasma. These two types of correlated ion stopping are of rather different character. We describe and explain these differences and give some generic examples of ion structures and ion clusters to demonstrate the basic features of both types of correlated stopping. This shows that only the short-range correlations always yield an enhanced stopping, whereas the long-range correlations, in general, reduce the stopping compared to single, individual ions. We mainly consider classical plasmas; the basic features, however, remain unchanged for a jellium target as well as for a plasma at any degeneracy.

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Pseudorapidity distribution and cluster formation in 50 and 400 GeV/c hadron–nucleus interactions

Canadian Journal of Physics ◽

10.1139/p84-037 ◽

1984 ◽

Vol 62 (3) ◽

pp. 230-238 ◽

Cited By ~ 5

Author(s):

M. Irfan ◽

H. Khushnood ◽

A. Shakeel ◽

A. R. Khan ◽

M. Shafi

Keyword(s):

Long Range ◽

Short Range ◽

Dominant Role ◽

Cluster Formation ◽

Pseudorapidity Distribution ◽

Appreciable Change ◽

Long Range Correlations ◽

Rapidity Gap ◽

Rapidity Distributions ◽

Short Range Correlations

From the study of the pseudorapidity, η, distributions of charged shower particles produced in 50 GeV/c π− – nucleus and 400 GeV/c proton (p)–nucleus collisions, and their dependence on various parameters, the maxima of η distributions are noticed to shift towards smaller values of η with increasing Ng. Bimodality in the η distributions for all Ng groups has been observed to be completely absent in 50 GeV/c π− – nucleus interactions. Furthermore, the value of [Formula: see text] is found to decrease monotonically with increasing Ng, Ns, and Nh. The dispersions of the rapidity distributions D(η) do not, however, demonstrate any tendency of appreciable change with increasing Ng, except in the region of small Ng values. Finally, study of rapidity-gap length distributions reveals that the two-particle short-range correlations play a dominant role while the contribution of long-range correlations seems to be quite small.

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Neutrinoless double β-decay nuclear matrix elements within the SRQRPA with self-consistent short range correlations

10.1063/1.3266097 ◽

2009 ◽

Cited By ~ 1

Author(s):

Petr Beneš ◽

Fedor Šimkovic ◽

Osvaldo Civitarese ◽

Ivan Stekl ◽

Jouni Suhonen

Keyword(s):

Nuclear Matrix ◽

Short Range ◽

Matrix Elements ◽

Β Decay ◽

Self Consistent ◽

Double Β Decay ◽

Short Range Correlations

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PAIRING OF STRONGLY CORRELATED NUCLEONS

International Journal of Modern Physics B ◽

10.1142/s0217979207043750 ◽

2007 ◽

Vol 21 (13n14) ◽

pp. 2395-2406

Author(s):

W. H. DICKHOFF

Keyword(s):

Short Range ◽

Mean Field ◽

Strongly Correlated ◽

Monte Carlo Calculations ◽

Self Consistent ◽

Complete Treatment ◽

Pure Neutron Matter ◽

Proton Pairing ◽

Finite Nuclei ◽

Short Range Correlations

Pairing properties of infinite matter are surveyed that are obtained from self-consistent Green's function calculations. A complete treatment of off-shell propagation that incorporates the effects of short-range correlations is included. Mean-field calculations based on the BCS approach are superseded by the present results, which resolve a long-standing puzzle associated with 3S1-3D1 (proton-neutron) pairing in symmetric nuclear matter. Results for 1S0 pairing in pure neutron matter are in agreement with recent Monte-Carlo calculations for this system. The possibility of proton pairing in finite nuclei, as a result of increasing proton correlations with increasing nucleon asymmetry, is pointed out.

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AN ELLIPSOIDAL MOLECULES MODEL OF LIQUID CRYSTAL WITH QUADRUPOLAR INTERACTION: SELF-CONSISTENT FREE ENERGY

International Journal of Modern Physics B ◽

10.1142/s0217979290000802 ◽

1990 ◽

Vol 04 (09) ◽

pp. 1589-1609

Author(s):

M.G. RASETTI ◽

M.L. RASTELLO

Keyword(s):

Single Molecule ◽

Short Range ◽

Lattice Gas ◽

Mean Field ◽

Second Order ◽

Classical Lattice ◽

Field Approach ◽

Self Consistent ◽

Short Range Correlations ◽

Second Order Phase Transition

We study the structure of the phase space for a system of N molecules of ellipsoidal symmetry, as a function of concentration and temperature. A classical lattice gas approximation is considered and a single molecule is described by a rigid ellipsoidal core with weak attractive tails along the long axis. The method adopted is a second-order mean-field approach – designed in such a way as to keep into account the fluctuations from equilibrium of the order parameters up to the fourth order – combined with a cumulant-cluster expansion, and improved by keeping track of the short-range correlations. Preliminary numerical calculations show the existence, in the case of zero attractive tail, of a second order phase transition.

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