International Journal of Modern Physics E

The use of radioactive beams opens a new frontier for fusion studies. The coupling to the continuum can be explored with very loosely bound nuclei. Experiments were performed with beams of nuclei at or near the proton and neutron drip-lines to measure fusion and associated reactions in the vicinity of the Coulomb barrier. In addition, the fusion yield is predicted to be enhanced in reactions involving very neutron-rich unstable nuclei. Experimental measurements were carried out to investigate if it is feasible to use such beams to produce new heavy elements. The current status of these experimental activities is given in this review.

A new composite model for leptons and quarks is presented. The model treats leptons and quarks as composites of three kinds of spin-½ particles (rishons), which belong to a fundamental triplet representation of a flavor SU(3) symmetry. A super-strong color-type force binds rishons together to form colorless leptons or quarks. Quarks display a valence property, which corresponds to the quark color of the Standard Model. Leptons have no valence property and are inert with respect to the super-strong color interaction. Both the strong color force and the weak interaction of the Standard Model are residual interactions of the super-strong color force in the new model.

We have used the Peierls–Yoccoz method to remove the center-of-mass energy of nuclei in the framework of mean-field sigma-omega models. The method is illustrated using small nuclei, such as the alpha particle and the nucleon itself. A quantized Hamiltonian of the model is required to implement the method. Nuclei are bound states of bare nucleons stabilized through the interactions with sigma and omega meson fields, which are described by coherent states. The quantized Hamiltonian contains a two-body quartic fermion interaction and it is shown that the exchange term has a large effect on the energy.

The effects of strong magnetic fields on the inner crust of neutron stars are investigated after taking into account the anomalous magnetic moments of nucleons. The energy spectra and wave functions for protons and neutrons in a uniform magnetic field are provided. The particle spin polarizations and the yields of protons and neutrons are calculated in a free Fermi gas model. Obvious spin polarizations occur when B≥10¹⁴G for protons and B≥10¹⁷G for neutrons, respectively. It is shown that the neutron spin polarization depends solely on the magnetic field strength.

The influence of the intruder level on vibrational modes in atomic nuclei is examined within the framework of the nucleon-pair shell model truncated to a SD-subspace. The vibrational character of the spectra is found to depend upon the size of the active model space and not on the parity of the populated levels.

This work follows our previous calculations of the ground state binding energy, size, and the effective nuclear charge of the muonic T₃ molecule, using the Born–Oppenheimer adiabatic approximation. In our past articles, we showed that the system possesses two minimum positions, the first one at the muonic distance and the second at the atomic distance. Also, the symmetric planner vibrational model assumed between the two minima and the approximated potential were calculated. Following from the previous studies, we now calculate the fusion rate of the T₃ muonic molecule according to the overlap integral of the resonance nuclear compound nucleus and the molecular wave functions.

We study the intermittent and fractal behavior of the emission spectrum of target-associated fast particles from ⁸⁴Kr-AgBr interactions at 0.95 GeV/A. We used χ(cos θ) as the phase space variable. Normalized or scaled factorial moments studies for various orders of moment q = 2–5, confirmed the intermittent behavior. G_q moments have a fractal interpretation in their fluctuation in phase space. Our studies reveal the multi-fractal behavior of the emission spectrum.

The spectra, E2-transition probabilities and electric quadrupole moments of a series of known superheavy nuclei, with Z between 102 and 112 are analyzed within the non-adiabatic model of quadrupole deformed, axially-symmetric nuclei. Calculations are made assuming that the mass parameter and the non-dimensional parameter g appearing in this model are constant for the superheavy nuclei with close charge numbers.

We demonstrate in this note, that an underlying non-commutative geometry of space time leaves an experimental footprint, that is, the Landau levels.

We evaluated the information entropies in coordinate and momentum spaces and their sum (S_r, S_k, S) for many nuclei using "experimental" densities or/and momentum distributions. The results are compared with the harmonic oscillator model and with the short-range correlated distributions. Suppose A is the number of nuclei, it is found that S_r depends strongly on ln A and does not depend very much on the model. The behavior of S_k is the opposite. The various cases that we consider can be classified according to either the quantity of the experimental data that we use or by the values of S, i.e., the increase in the quality of the density and in the momentum distributions leads to an increase in the values of S. In all cases, apart from the linear relation S=a+b ln A, the linear relation S=a_V+b_Vln V also holds. V is the mean volume of the nucleus. If S is considered as an ensemble entropy, a relation between A or V and the ensemble volume can be found. Finally, comparing many different electron scattering experiments for the same nucleus, we found that the larger the momentum transfer ranges, the larger the information entropy is. It is concluded that S might be used to compare different experiments for the same nucleus, and to choose the most reliable one.