International Journal of Modern Physics E

The accuracy of multipole expansion of density distribution for deformed nuclei is tested. The interaction potential for a deformed-spherical pair of nuclei was calculated using the folding model derived from zero-range nucleon–nucleon (NN) interaction. We considered two spherical projectiles Ca⁴⁰ and Pb²⁰⁸ scattered on U²³⁸ deformed target nucleus. The error in the heavy ion (HI) potential resulting from using a truncated multipole density expansion is evaluated for each case in the presence of octupole deformation δ₃ besides quadrupole δ₂. We are interested in the value of error for R ≥ R_T (touching distance). We found that for values of |δ₃|≤0.1 the error at R = R_T reaches reasonable values when six terms expansion is used. For |δ₃| = 0.2, we calculated the Coulomb barrier parameters using realistic NN force and found that the large error present in six terms for zero range force decreases strongly to less than 1% when the zero range is added to finite range forces and Coulomb interaction to form the Coulomb barrier. It is noted that the negative value of octupole deformation parameters δ₃ = -0.1 produce error at orientation angle θ equal in value to that produced at angle (180°-θ) for the positive values δ₃ = 0.1. We also found that the error decreases as the mass number of the projectile nucleus increases.

The location of the proton dripline in a new phenomenological mass formula is calculated. Predictions of different mass formulas for the dripline are compared. The implications of the new mass formula for rapid proton nucleosynthesis beyond ⁵⁶Ni are discussed. It is seen that the new formula indicates that masses up to A = 80 are easily synthesized in a typical X-ray burst.

The reaction ⁹⁶Mo(d, p)⁹⁷Mo has been studied at 12 MeV using the tandem Van de Graaff accelerator and a multi-channel magnetic spectrograph at the Atomic Weapon Research Establishment, Aldermaston, England. Angular distributions of protons are measured at 12 different angles from 5° to 87.5° at an interval of 7.5° and the reaction products are detected in nuclear emulsion plates. Thirty levels in the energy range from 0.000 to 2.458 MeV have been observed and absolute differential cross-sections for these levels have been measured. The data are analyzed in terms of the distorted-wave Born approximation (DWBA) theory of the direct reactions, and spins, parities and spectroscopic factors are deduced for various levels. Ambiguity in the spin assignments of d_5/2 and d_3/2 which is allowed in l_n = 2(d, p) transition is removed by using the corresponding L-value of the ⁹⁵ Mo(t, p)⁹⁷Mo reaction at E_t = 12 MeV. Determined value of the sum of spectroscopic factors for transfers of d_5/2 neutrons suggests configuration mixing in the ground state of ⁹⁶Mo. The properties of the levels in ⁹⁷Mo are compared with previous experimental results and theoretical predictions.

The relativistic six-quark equations are found in the framework of the dispersion relation technique. The approximate solutions of these equations using the method based on the extraction of leading singularities of the heavy hexaquark amplitudes are obtained. The relativistic six-quark amplitudes of dibaryons including the light quarks u, d and heavy quarks c, b are calculated. The poles of these amplitudes determine the masses of charmed and bottom dibaryons with the isospins , , .

We estimate the time reversal violations for neutrino oscillations in matter for typical experimental energies and baselines. We examine the present status of experiments on neutrino oscillations, propose experiments for TRV, and discuss the future.

We present the investigation of the neutrino-induced strangeness associated production on nuclei in the relativistic plane wave impulse approximation (RPWIA) framework at the intermediate neutrino energies. In this study, the elementary hadronic weak amplitudes are embedded inside the nuclear medium for the description of the exclusive channels of neutrino–nucleus interactions. These amplitudes are extracted using a model-dependent evaluation of the hadronic vertex using the Born term approximation in which the application of the Cabibbo V–A theory and SU(3) symmetry are assumed to be valid. The nuclear effects are included via the bound state wave functions of the nucleon obtained from the relativistic mean field (RMF) models. Two kinematics settings are used to examine various distributions of the differential cross-section in the rest frame of the target nuclei. The numerical results are obtained for the neutrino-induced charged-current (CC) K⁺Λ-production on bound neutrons in 1s^1/2 and 1p^3/2 orbitals of ¹²C. The angular distributions are forward peaked under both kinematic settings, whereas under the quasifree setting, the cross-sections tend to mimic the missing momentum distribution of the bound nucleon inside the nucleus.

We calculate the one-neutron removal reaction cross-section (σ_-1n) for a few stable and neutron-rich Boron and Carbon halo nuclei with ¹²C as target, using relativistic mean field (RMF) densities, in the frame work of Glauber model. The results are compared with the experimental data. Study of the stable nuclei with the deformed densities have shown a good agreement with the data. However, it differs significantly for the halo nuclei. We observe that while estimating the σ_-1n value from the difference of reaction cross-sections of two neighboring nuclei with mass number A and that of A-1 in an isotopic chain, we get good agreement with the known experimental data for the halo cases.

In this work we study the process e⁺+e^-→J/Ψ+η_c at energy observed recently at B-factories whose measurements were made by Babar and Belle groups. We calculate the cross-section for this process in the Bethe–Salpeter formalism under Covariant Instantaneous Anstaz. To simplify our calculation, the heavy quark approximation is employed in the quark and gluon propagators. In the exclusive process of e⁺e^- annihilation into two heavy quarkonia, the cross-section calculated in this scenario is compatible with the experimental data of Babar and Belle.