TY - JOUR

T1 - Random interactions, isospin, and the ground states of odd-A and odd-odd nuclei

AU - Horoi, Mihai

AU - Volya, Alexander

AU - Zelevinsky, Vladimir

PY - 2002/8/1

Y1 - 2002/8/1

N2 - It was recently shown that the ground state quantum numbers of even-even nuclei have a high probability to be reproduced by an ensemble of random but rotationally invariant two-body interactions. In the present work we extend these investigations to odd-A and odd-odd nuclei, considering in particular the isospin effects. Studying the realistic shell model as well as the single-j model, we show that random interactions have a tendency to assign the lowest possible total angular momentum and isospin to the ground state. In the sd shell model this reproduces correctly the isospin but not the spin quantum numbers of actual odd-odd nuclei. An odd-even staggering effect in probability of various ground state quantum numbers is present for even-even and odd-odd nuclei, while it is smeared out for odd-A nuclei. The observed regularities suggest the underlying mechanism of bosonlike pairing of fermionic pairs in T = 0 and T = 1 states generated by the off-diagonal matrix elements of random interactions. The relation to the models of random spin interactions is briefly discussed.

AB - It was recently shown that the ground state quantum numbers of even-even nuclei have a high probability to be reproduced by an ensemble of random but rotationally invariant two-body interactions. In the present work we extend these investigations to odd-A and odd-odd nuclei, considering in particular the isospin effects. Studying the realistic shell model as well as the single-j model, we show that random interactions have a tendency to assign the lowest possible total angular momentum and isospin to the ground state. In the sd shell model this reproduces correctly the isospin but not the spin quantum numbers of actual odd-odd nuclei. An odd-even staggering effect in probability of various ground state quantum numbers is present for even-even and odd-odd nuclei, while it is smeared out for odd-A nuclei. The observed regularities suggest the underlying mechanism of bosonlike pairing of fermionic pairs in T = 0 and T = 1 states generated by the off-diagonal matrix elements of random interactions. The relation to the models of random spin interactions is briefly discussed.

UR - http://www.scopus.com/inward/record.url?scp=0036702718&partnerID=8YFLogxK

U2 - 10.1103/PhysRevC.66.024319

DO - 10.1103/PhysRevC.66.024319

M3 - Article

AN - SCOPUS:0036702718

VL - 66

SP - 243191

EP - 2431911

JO - Physical Review C - Nuclear Physics

JF - Physical Review C - Nuclear Physics

SN - 0556-2813

IS - 2

M1 - 024319

ER -