Pairing and isospin symmetry in proton-rich nuclei

نویسنده

  • J. Engel
چکیده

Unlike their lighter counterparts, most odd-odd N = Z nuclei with mass A > 40 have ground states with isospin T=1, suggesting an increased role for the isovector pairing interaction. A simple SO(5) seniority-like model of this interaction reveals a striking and heretofore unnoticed interplay between likeparticle and neutron-proton isovector pairing near N = Z that is reflected in the number of each kind of pair as a function of A and T . Large scale shellmodel calculations exhibit the same trends, despite the simultaneous presence of isoscalar pairs, deformation, and other correlations. 21.10-k,21.60.Fw,21.60.Ka Typeset using REVTEX

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Isospin Symmetry Breaking in an Algebraic Pairing Sp(4) Model

An exactly solvable sp(4) algebraic approach extends beyond the traditional isospin conserving nuclear interaction to bring forward effects of isospin symmetry breaking and isospin mixing resulting from a two-body nuclear interaction that includes proton-neutron (pn) and like-particle isovector pairing correlations plus significant isoscalar pn interactions. The model yields an estimate for the...

متن کامل

Isospin singlet (pn) pairing and quartetting contribution to the binding energy of nuclei

The structure of nuclei is understood to a large extent within a single-particle approach, the nuclear shell model which was introduced in nuclear theory 50 years ago [1]. Its microscopic foundation should be given from a quantum statistical treatment of the many-nucleon system, where in general also the concept of temperature can be introduced to describe excited nuclei in a dense medium. With...

متن کامل

ar X iv : n uc l - th / 9 70 20 47 v 1 2 1 Fe b 19 97 Neutron - proton pairing in the BCS approach

We investigate the BCS treatment of neutron-proton pairing involving timereversed orbits. We conclude that an isospin-symmetric hamiltonian, treated with the help of the generalized Bogolyubov transformation, fails to describe the ground state pairing properties correctly. In order for the np isovector pairs to coexist with the like-particle pairs, one has to break the isospin symmetry of the h...

متن کامل

X iv : n uc l - th / 9 80 50 15 v 1 6 M ay 1 99 8 Pairing and symmetry energy in N ≃ Z nuclei

It is shown that in N ≃ Z nuclei the effects of isovector pairing and the symmetry energy are intimately related. In particular, in the odd-odd N = Z nuclei these two effect are essentially equal in magnitude, causing near degeneracy of the lowest T = 1 and T = 0 states and appearance of the T = 1 ground state isospin in many such nuclei. To illustrate the validity of the considerations present...

متن کامل

Relativistic mean-field description of nuclei at the drip-lines

We present a review of recent applications of the relativistic mean-field theory to the structure of nuclei close to the drip-lines. For systems with extreme isospin values, the relativistic Hartree-Bogoliubov model provides a unified and self-consistent description of mean-field and pairing correlations. The model has been applied in studies of structure phenomena that include: formation of ne...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 1996