Electric dipole moment of light nuclei in chiral effective field theory

CP-violating interactions at quark level generate CP-violating nuclear interactions and currents, which could be revealed by looking at the presence of a permanent nuclear electric dipole moment. Within the framework of chiral effective field theory, we discuss the derivation of the CP-violating nuclear potential up to next-to-next-to leading order (N2LO) and the preliminary results for the charge operator up to next-to leading order (NLO). Moreover, we introduce some renormalization argument which indicates that we need to promote the short-distance operator to the leading order (LO) in order to reabsorb the divergences generated by the one pion exchange. Finally, we present some selected numerical results for the electric dipole moments of 2H, 3He and 3H discussing the systematic errors introduced by the truncation of the chiral expansion.

The Ξ-nuclear potential constrained by recent Ξ– hypernuclei experiments

The $\Xi$-nuclear potential is investigated in the quark mean-field (QMF) model based on recent results of the $\Xi^-+^{14}\rm{N}$ ($_{\Xi^-}^{15}\rm{C}$) system. The experimental data on the binding energy of $1p$-state $\Xi^-$ hyperon in $_{\Xi^-}^{15}\rm{C}$ hypernuclei in KISO, IBUKI, E07-T011, E176-14-03-35 events are merged as $B_{\Xi^-}(1p)=1.14\pm0.11$ MeV. With this constraint, the coupling strengths between the $\omega$ vector meson and $\Xi$ hyperon are fixed in three QMF parameter sets. At the same time, the $\Xi^-$ binding energy of $1s$ state in $_{\Xi^-}^{15}\rm{C}$ is predicted as $B_{\Xi^-}(1s)=5.66\pm0.38$ MeV with the same interactions, completely consistent with the data from the KINKA and IRRAWADDY events. Finally, the $\Xi$-nuclear potential is calculated in the symmetric nuclear matter in the framework of QMF models. It is $U_{\Xi }=-11.96\pm 0.85$ MeV at nuclear saturation density, which will be essential to determine the onset density of $\Xi$ hyperon in neutron star.

Effect of Surface Diffuseness Parameter on Quasi-elastic Scattering Calculations for 16O+208Pb,63Cu Systems

A systematic study on the surface characteristic of the nucleus-nucleus potential for some heavy-ion. The nuclear potential has been described by using Woods-Saxon (WS), the single-channel (SC) and the coupled-channels (CC) calculations, which were between the relative motion of the colliding nuclei and their intrinsic motions, were conducted to study its influence on calculation, the ratio of the quasi-elastic to the Rutherford cross sections and probe the surface diffuseness method was used to find the best fitted value of the diffuseness parameters in comparison with the experimental data. We find that the best fitted value of the diffuseness parameter which obtained through a coupled-channel calculation with inert target and excited projectile forIn the current work, the single-channel (SC) and the coupled-channels (CC) calculations, which were between the relative motion of the colliding nuclei and their intrinsic motions, were conducted to study its influence on calculation, the ratio of the quasi-elastic to the Rutherford cross sections and probe the surface diffuseness find that the best fitted value of the diffuseness parameter which obtained through a coupled-channel calculation with excited target and projectile excited also inert projectile-excited target for the 16O+208Pb andexcited projectile and inert target for the 16O+63Cu.

Alpha decay half-lives of superheavy nuclei 104 ≤ Z ≤ 125

In order to describe scattering, fusion, fission and ground state masses, Krappe and collaborators developed unified nuclear potential, by generalizing liquid drop model. They have incorporated phenomenological parameters accounting for the attractive force between two separated fragments. One of the phenomenological parameters involved in this model is the range of folded Yukawa function, which accounts for surface diffuseness of the potential and short range attractive interaction. The role of range of folding function of Yukawa-plus-exponential potential is analyzed for alpha decay of heavy and superheavy nuclei. Significant effect of this function is noted in preformation probability which improves the accuracy of half-lives of alpha decay. Half-lives for alpha decay are better obtained for two values of the range of folding function 0.54 and 0.8[Formula: see text]fm for heavy and superheavy mass regions, respectively. The study confirms the associated shell structure [Formula: see text] in heavy nuclei and [Formula: see text] and [Formula: see text] in superheavy nuclei. The calculations are extended to predict the half-lives of superheavy nuclei with [Formula: see text] and [Formula: see text] which are not yet synthesized experimentally.

Binary and Ternary Fragmentation Analysis of 252Cf Nucleus using Different Nuclear Radii

Pioneering study reveals that a radioactive nucleus may split into two or three fragments and the phenomena are known as binary fission and ternary fission respectively. In order to understand the nuclear stability and related structure aspects, it is of huge interest to explore the fragmentation behavior of a radioactive nucleus in binary and ternary decay modes. In view of this, Binary and ternary fission analysis of 252Cf nucleus is carried out using quantum mechanical fragmentation theory (QMFT). The nuclear potential and Coulomb potential are estimated using different versions of radius vector. The fragmentation structure is found to be independent to the choice of fragment radius for binary as wellas ternary decay paths. The deformation effect is included up to quadrupole (β2) with optimum cold orientations and their influence is explored within binary splitting mode. Moreover, the most probable fission channels explore the role of magic shell effects in binary and ternary fission modes.

Comparative Analysis of Woods-Saxon and Yukawa Model Nuclear Potentials

In this paper, we model the nuclear potential using Woods-Saxon and Yukawa interaction as the mean field in which each nucleon experiences a central force due to rest of the nucleons. The single particle energy states are obtained by solving the time independent Schrodinger wave equation using matrix diagonalization method with infinite spherical well wave-functions as the basis. The best fit model parameters are obtained by using variational Monte-Carlo algorithm wherein the relative mean-squared error, christened as chi-squared value, is minimized. The universal parameters obtained using Woods-Saxon potential are found to be matched with literature reported data resulting a chi-square value of 0.066 for neutron states and 0.069 for proton states whereas the chi-square value comes out to be 1.98 and 1.57 for neutron and proton states respectively by considering Yukawa potential. To further assess the performance of both the interaction potentials, the model parameters have been optimized for three different groups, light nuclei up to 16O - 56Ni, heavy nuclei 100Sn - 208Pb and all nuclei 16O - 208Pb. It is observed that Yukawa model performed reasonably well for light nuclei but did not give satisfactory results for the other two groups while Woods-Saxon potential gives satisfactory results for all magic nuclei across the periodic table.