##### Dr. Daniel Negrea

My research interests are focused on the domain of theoretical nuclear physics; in particular, on the nuclear structure of finite nuclear systems. I’m exploiting this physics branch by studying nuclear pairing phenomena such as like-particle pairing (neutron and proton pairs) and proton-neutron pairing both isovector and isoscalar. To carry out these studies, I use many-body techniques, the programming language FORTRAN and symbolic computer algebra for analytical derivations. Related to these subjects, I’m developing a new model called the Quartet Condensation Model (QCM). This model aims to describe the isovector and isoscalar pairing correlations in terms of quartets rather than Cooper pairs. This approach has the great advantage of conserving exactly the particle number and the total isospin in the ground state of even-even N=Z and N>Z nuclei, but also of odd-odd N=Z nuclei. By self-consistent calculations QCM is able to describe well the symmetry and Wigner energies. Applications for excited states of such nuclei are also considered.

- N. Sandulescu, D. Negrea, J. Dukelsky, and C. W. Johnson,
*Quartet condensation and isovector pairing correlations in N=Z nuclei,*Phys. Rev. C 85, 061303(R) (2012). - N. Sandulescu, D. Negrea, and C. W. Johnson,
*Four-nucleon α-type correlations and proton-neutron pairing away from the N=Z line,*Phys. Rev. C 86, 041302(R) (2012). - D. Negrea and N. Sandulescu,
*Isovector proton-neutron pairing and Wigner energy in Hartree-Fock mean field calculations,*Phys. Rev. C 90, 024322 (2014). - D. Negrea, N. Sandulescu, and D. Gambacurta,
*Isovector and isoscalar pairing in odd–odd N = Z nuclei within a quartet approach,*Prog. Theor. Exp. Phys. 2017, 073D05 - D. Negrea, P. Buganu, D. Gambacurta, and N. Sandulescu,
*Isovector and isoscalar proton-neutron pairing in N>Z nuclei,*Phys. Rev. C 98 (2018) 064319.