International Journal of Modern Physics E

The physics potential of the search is summarized. Past experiments and the challenges discovered in them are reviewed. The innovative methods employed by the current experiment are discussed. Future experimental prospects are given.

The present work reports the use of nuclear transparency effect of protons in proton– and deuteron–carbon interactions at 4.2A GeV/c to get information about the states of nuclear matter. The "half-angle" technique is used to extract the information on nuclear transparency. The results are compared with Dubna version of Cascade model. The average values of multiplicity, momentum and transverse momentum of protons are analyzed as a function of the number of identified protons in an event. We observed some evidence and trends in the data, which could be considered as transparency effect. Analysis of the results shows that the leading effect is the basis of the observed transparency. Some contribution to the observed effect could be the existing short range correlations and the scaling power law s^-N, for exclusive two-body hard scattering.

Spin breaking for the resonant states in ²⁰⁸Pb is investigated by solving the Dirac equation with Woods–Saxon vector and scalar potentials in combination with an analytic continuation in the coupling constant method, where the stable and convergent energies and widths are obtained. Spin breaking are shown in correlation with the nuclear mean field shaped by the central depth Σ₀, a radius (range) R and a diffusivity a, which play an important role in the splittings of energy and width. The energy-level crossings appear in several spin partners of resonant states, where the decay time is found to be different for the spin doublets even when their energies are fully degenerate.

Approximate analytical solutions of the Dirac equation with the trigonometric Pöschl–Teller (tPT) potential are obtained for arbitrary spin-orbit quantum number κ using an approximation scheme to deal with the spin-orbit coupling terms κ(κ±1)r^-2. In the presence of exact spin and pseudo-spin (p-spin) symmetric limitation, the bound state energy eigenvalues and the corresponding two-component wave functions of the Dirac particle moving in the field of attractive and repulsive tPT potential are obtained using the parametric generalization of the Nikiforov–Uvarov (NU) method. The case of nonrelativistic limit is studied too.

Relativistic Dirac coupled channel analyses using optical potential model are performed for the 800 MeV proton inelastic scatterings from ²⁶Mg and the results are compared with those from several other axially symmetric deformed nuclei for the systematic Dirac analyses. Employing scalar-vector model, scalar and time-like vector optical potentials in Lorentz covariant form are calculated phenomenologically by solving Dirac coupled channel equations using sequential iteration method. Dirac equations are reduced to second-order differential equations to obtain Schrödinger equivalent effective central and spin-orbit optical potentials and it is found that the heavier deformed nucleus has the larger effective central potential strength. Using the first-order rotational collective model to describe the low-lying excited states of ground state rotational band in the deformed nuclei, deformation parameters for the excited states are calculated and it is observed that the lighter deformed nucleus has the larger deformation parameter for the lowest lying excited 2⁺ state at the 800 MeV proton inelastic scattering, indicating the stronger coupling to the ground state compared to that of heavier nucleus.

For the first time, we present a theoretical formulation to determine the nonrelativistic repulsive optical potential relative to neutron–nucleus interaction in terms of the s-wave coherent scattering amplitude and the radius of the nucleus which is regarded as a spherical infinite potential well. Within this context, the Fermi velocity is determined in excellent agreement with the Fermi velocity obtained from considerations relative to nuclear density obeying the Saxon–Woods distribution. Assuming this distribution, the force relative to the neutron–nucleus interaction is calculated. Aspects related to the involved chemical potential are discussed. Our results are consistent with previous work.

The one-proton and two-proton separation energies are studied for "ordinary" and rare-earth proton-rich nuclei by including the isovector neutron–proton (np) pairing correlations using the BCS approximation. Even–even as well as odd nuclei are considered. In the latter case, the wave function is defined using the blocked-level technique. The single-particle energies used are those of a deformed Woods–Saxon mean field. It is shown that the np isovector pairing effects on the one-proton and two-proton separation energies are non-negligible. However, the only isovector BCS approximation seems to be inadequate for a good description of these quantities when including the np pairing effects: either a particle-number projection or the inclusion of the isoscalar pairing effect seems to be necessary. Another possible improvement would be a more realistic choice of the pairing strengths.

The properties of the yrast states for ^100-110Pd even–even (e–e) nuclei have been established. The relation between the moment of inertia 2ϑ/ℏ² and the square of the rotational energy (ℏω)² has been drawn to identify the back-bending that may occur at a certain state for each isotope. The relation between gamma-energy over spin Eγ/I as a function of spin I has been drawn to determine the evolution in each isotope ranging from vibration to rotational properties. The suitable limit in the interacting boson model IBM-1 has been used to calculate the yrast states for each isotope, which are then compared with the experimental results.

We discuss scaling laws of fusion yields generated by laser-plasma interactions. The yields are found to scale as a function of the laser power. The origin of the scaling law in the laser driven fusion yield is derived in terms of hydrodynamic scaling. We point out that the scaling properties can be attributed to the laser power dependence of three terms: the reaction rate, the density of the plasma and the projected range of the plasma particle in the target medium. The resulting scaling relations have a predictive power that enables estimating the fusion yield for a nuclear reaction which has not been investigated by means of the laser accelerated ion beams.

For the Riemannian space, built from the collective coordinates used within nuclear models, an additional interaction with the metric is investigated, using the collective equivalent to Einstein's curvature scalar. The coupling strength is determined using a fit with the AME2003 ground state masses. An extended finite-range droplet model including curvature is introduced, which generates significant improvements for light nuclei and nuclei in the trans-fermium region.