T. Babacan

The effect of the pairing interaction on the energies of isobar analogue resonances in 112-124Sb and isospin admixture in 100-124Sn isotopes

In the present study, the effect of the pairing interaction and the isovector correlation between nucleons on the properties of the isobar analogue resonances (IAR) in 112–124Sb isotopes and the isospin admixture in 100–124Sn isotopes is investigated within the framework of the proton–neutron quasi-particle random phase approximation (pnQRPA). The form of the interaction strength parameter is related to the shell-model potential by restoring the isotopic invariance of the nuclear part of the total Hamiltonian. In this respect, the isospin admixtures in the 100–124Sn isotopes are calculated, and the dependence of the differential cross section and the volume integral JF for the Sn(3He,t)Sb reactions at E(3He) =200 MeV occurring by the excitation of IAR on mass number A is examined. Our results show that the calculated value for the isospin mixing in the 100Sn isotope is in good agreement with Colo et als estimates (4–5%), and the obtained values for the volume integral change within the error range of the value reported by Fujiwara et al (53 ± 5 MeV fm3). Moreover, it is concluded that although the differential cross section of the isobar analogue resonance for the (3He,t) reactions is not sensitive to pairing correlations between nucleons, a considerable effect on the isospin admixtures in N ≈ Z isotopes can be seen with the presence of these correlations.

The isospin admixture of the ground state and the properties of the isobar analog resonances in medium and heavy mass nuclei

Within the framework of quasiparticle random phase approximation (QRPA), Pyatov-Salamov method [23] for the self-consistent determination of the isovector effective interaction strength parameter, restoring a broken isotopic symmetry for the nuclear part of the Hamiltonian, is used. The isospin admixtures in the ground state of the parent nucleus, and the isospin structure of the isobar analog resonance (IAR) state were investigated with the inclusion of the pairing correlations between nucleons for the medium and heavy mass regions: 80 <A < 90, 102 <A < 124, and 204 <A < 214. It was determined that the influence of the pairing interaction between nucleons on the isospin admixtures in the ground state and the isospin structure of the IAR state is more pronounced for the light isotopes (N ≈ Z) of the investigated nuclei

An investigation of the influence of the pairing correlations on the properties of the isobar analog resonances inA = 208 nuclei

Within the quasi-particle random phase approximation (QRPA), the method of the self-consistent determination of the isovector effective interaction which restores a broken isotopic symmetry for the nuclear part of the Hamiltonian is given. The effect of the pairing correlations between nucleons on the following quantities were investigated for theA = 208 nuclei: energies of the isobar analog 0+ states, the isospin admixtures in the ground state of the even-even nuclei, and the differential cross-section for the208Pb(3He,t)208Bi reaction atE(3He)=450 MeV. Both couplings of the excitation branches withTz = T0 ± 1, and the analog state with isovector monopole resonance (IVMR) in the quasi-particle representation were taken into account in our calculations. As a result of these calculations, it was seen that the pairing correlations between nucleons have no considerable effect on theT = 23 isospin admixture in the ground state of the208Pb nucleus, and they cause partially an increase in the isospin impurity of the isobar analog resonance (IAR). It was also established that these correlations have changed the isospin structure of the IAR states, and shifted the energies of the IVMR states to the higher values.

Study of Gamow–Teller transitions in isotopes of titanium within the quasi particle random phase approximation

The Gamow–Teller (GT) transition is inarguably one of the most important nuclear weak transitions of the spin-isospin στ type. It has many applications in nuclear and astrophysics. These include, but are not limited to, r-process β-decays, stellar electron captures, neutrino cooling rates, neutrino absorption and inelastic scattering on nuclei. The quasiparticle random phase approximation (QRPA) is an efficient way to generate GT strength distribution. In order to better understand both theoretical systematics and uncertainties, we compare the GT strength distributions, centroid and width calculations for

Calculation Of Two Neutrino Double Beta Decay Nuclear Matrix Elements For 128,130Te

{^{40\mbox{--}60}\mathrm{Ti}}

Associative photoproduction of Roper resonance and ω meson

isotopes, using the pn-QRPA, Pyatov method (PM) and the Schematic model (SM). The pn-QRPA and SM are further sub-divided into three categories in order to highlight the role of particle-particle (pp) force and deformation of the nucleus in the GT strength calculations. In PM, we study only the influence of the pp force in the calculation. We also compare with experimental results and other calculations where available. We found that the inclusion of pp force and deformation significantly improves the performance of SM and pn-QRPA models. Incorporation of pp force leads to pinning down the centroid value in the PM. The calculated GT strength functions using the pn-QRPA (C) and SM (C) models are in reasonable agreement with measured data.

Gamow-Teller 1 + states in Bi 208

Based on Pyatov‐Salamov method, spin‐isospin (Gamow‐Teller) effective interaction strength parameter has been found self‐consistently. Then, the problem has been solved within the framework of QRPA. Gamow‐Teller matrix elements for both β− and β+ transitions and two neutrino double beta decay nuclear matrix elements have been calculated for 128,130Te→128,130Xe transitions. The obtained results have been compared with the corresponding experimental data and other theoretical results.

Spin-isospin transitions in chromium isotopes within the quasiparticle random phase approximation

Associative photoproduction of

Self-consistent calculations of isospin admixtures in the ground states of the N=Z nuclei in the mass region of 50–100

\omega

Gamow-Teller 1+ states in 208Bi

-meson and