BruecknerG-matrix approach for neutron-proton pairing correlations in the deformed BCS approach

2015 ◽  
Vol 92 (4) ◽  
Author(s):  
Eunja Ha ◽  
Myung-Ki Cheoun ◽  
F. Šimkovic
2015 ◽  
Author(s):  
M. Fellah ◽  
N. H. Allal ◽  
M. R. Oudih

2012 ◽  
Vol 21 (12) ◽  
pp. 1250100 ◽  
Author(s):  
F. HAMMACHE ◽  
N. H. ALLAL ◽  
M. FELLAH

The one-proton and two-proton separation energies are studied for "ordinary" and rare-earth proton-rich nuclei by including the isovector neutron–proton (np) pairing correlations using the BCS approximation. Even–even as well as odd nuclei are considered. In the latter case, the wave function is defined using the blocked-level technique. The single-particle energies used are those of a deformed Woods–Saxon mean field. It is shown that the np isovector pairing effects on the one-proton and two-proton separation energies are non-negligible. However, the only isovector BCS approximation seems to be inadequate for a good description of these quantities when including the np pairing effects: either a particle-number projection or the inclusion of the isoscalar pairing effect seems to be necessary. Another possible improvement would be a more realistic choice of the pairing strengths.


2001 ◽  
Vol 64 (2) ◽  
Author(s):  
N. S. Kelsall ◽  
R. Wadsworth ◽  
A. N. Wilson ◽  
P. Fallon ◽  
A. O. Macchiavelli ◽  
...  

2008 ◽  
Vol 17 (01) ◽  
pp. 228-239 ◽  
Author(s):  
PHILIPPE QUENTIN ◽  
HOUDA NAIDJA ◽  
LUDOVIC BONNEAU ◽  
JOHANN BARTEL ◽  
HA THUY LONG

We present the key aspects of the theoretical foundations of the Higher Tamm–Dancoff Approximation which can be interpreted as a truncated shell-model approach based on a Hartree–Fock solution, ensuring the conservation of the particle number. Then we discuss some phenomenological aspects of the residual interactions used, namely the delta interaction to describe the neutron–neutron and proton–proton pairing correlations and the quadrupole–quadrupole interaction to describe vibrational correlations.


1999 ◽  
Vol 647 (3-4) ◽  
pp. 197-216 ◽  
Author(s):  
A. Petrovici ◽  
K.W. Schmid ◽  
Amand Faessler

2010 ◽  
Vol 19 (07) ◽  
pp. 1383-1409 ◽  
Author(s):  
S. KERROUCHI ◽  
N. H. ALLAL ◽  
M. FELLAH ◽  
M. DOUICI

Particle-number fluctuations effects on the beta transition probabilities are studied in the neutron–proton pairing framework. The Hamiltonian of the system has been considered in its most general form and has been diagonalized by means of the linearization method. However, since the generalized Bogoliubov–Valatin transformation obtained in this way leads to a quasi-particle Hamiltonian which is still nondiagonal, a rediagonalization has been performed. The corresponding wave functions have been projected on both the good neutron and proton numbers using a recently proposed method. Expressions of the beta transition probabilities which strictly conserve the particle-number have then been established. As a first step, the model has been numerically tested within the framework of the schematic one-level model. As a second step, nuclei such as N = Z has been studied using the single-particle energies and eigenstates of the Woods–Saxon deformed mean field. It has thus been shown the necessity of: (i) including the isovector pairing correlations, (ii) performing a rediagonalization of the Hamiltonian, (iii) performing a particle-number projection, (iv) carefully choice the pairing-strength values, when calculating the transition probabilities.


Sign in / Sign up

Export Citation Format

Share Document