Single-Particle States of an Electron-Ion Gas in the Random-Phase Approximation

1967 ◽  
Vol 153 (1) ◽  
pp. 187-200
Author(s):  
W. W. Zachary
Keyword(s):  
Single Particle ◽  
Random Phase Approximation ◽  
Random Phase ◽  
Phase Approximation

scholarly journals Estimation of nuclear matrix elements of double-$$\varvec{\beta }$$ decay from shell model and quasiparticle random-phase approximation

2021 ◽  
Vol 136 (9) ◽  
Author(s):  
J. Terasaki ◽  
Y. Iwata
Keyword(s):  
Shell Model ◽  
Nuclear Matrix ◽  
Single Particle ◽  
Random Phase Approximation ◽  
Random Phase ◽  
Nuclear Matrix Element ◽  
Phase Approximation ◽  
Quasiparticle Random Phase Approximation ◽  
Calculation Results ◽  
The Many

AbstractThe nuclear matrix element (NME) of neutrinoless double-$$\beta $$ β ($$0\nu \beta \beta $$ 0 ν β β ) decay is an essential input for determining the neutrino effective mass, if the half-life of this decay is measured. Reliable calculation of this NME has been a long-standing problem because of the diversity of the predicted values of the NME, which depends on the calculation method. In this study, we focus on the shell model and the QRPA. The shell model has a rich amount of the many-particle many-hole correlations, and the quasiparticle random-phase approximation (QRPA) can obtain the convergence of the calculation results with respect to the extension of the single-particle space. It is difficult for the shell model to obtain the convergence of the $$0\nu \beta \beta $$ 0 ν β β NME with respect to the valence single-particle space. The many-body correlations of the QRPA may be insufficient, depending on the nuclei. We propose a new method to phenomenologically modify the results of the shell model and the QRPA compensating for the insufficiencies of each method using the information of other methods in a complementary manner. Extrapolations of the components of the $$0\nu \beta \beta $$ 0 ν β β NME of the shell model are made toward a very large valence single-particle space. We introduce a modification factor to the components of the $$0\nu \beta \beta $$ 0 ν β β NME of the QRPA. Our modification method yields similar values of the $$0\nu \beta \beta $$ 0 ν β β NME for the two methods with respect to $$^{48}$$ 48 Ca. The NME of the two-neutrino double-$$\beta $$ β decay is also modified in a similar but simpler manner, and the consistency of the two methods is improved.

Interpretation of Preferential Adsorption Using Random Phase Approximation Theory

1995 ◽  
Vol 60 (10) ◽  
pp. 1641-1652 ◽  
Author(s):  
Henri C. Benoît ◽  
Claude Strazielle
Keyword(s):  
Approximation Theory ◽  
Random Phase Approximation ◽  
Virial Coefficient ◽  
Random Phase ◽  
Second Virial Coefficient ◽  
Solvent Mixture ◽  
Gyration Radius ◽  
Thermodynamic Quantities ◽  
Phase Approximation ◽  
Preferential Adsorption

It has been shown that in light scattering experiments with polymers replacement of a solvent by a solvent mixture causes problems due to preferential adsorption of one of the solvents. The present paper extends this theory to be applicable to any angle of observation and any concentration by using the random phase approximation theory proposed by de Gennes. The corresponding formulas provide expressions for molecular weight, gyration radius, and the second virial coefficient, which enables measurements of these quantities provided enough information on molecular and thermodynamic quantities is available.

Neutrino reactions onC12by the quasiparticle random-phase approximation (QRPA)

2010 ◽  
Vol 81 (2) ◽  
Author(s):  
Myung-Ki Cheoun ◽  
Eunja Ha ◽  
Su Youn Lee ◽  
K. S. Kim ◽  
W. Y. So ◽  
...  
Keyword(s):  
Random Phase Approximation ◽  
Random Phase ◽  
Phase Approximation ◽  
Quasiparticle Random Phase Approximation

scholarly journals Gas Transport across Carbon Nitride Nanopores: A Comparison of van der Waals Functionals against the Random-Phase Approximation

2021 ◽  
Author(s):  
Mohammad Tohidi Vahdat ◽  
Davide Campi ◽  
Nicola Colonna ◽  
Nicola Marzari ◽  
Kumar Varoon Agrawal
Keyword(s):  
Random Phase Approximation ◽  
Carbon Nitride ◽  
Gas Transport ◽  
Van Der Waals ◽  
Random Phase ◽  
Phase Approximation
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