International Journal of Modern Physics E

We discuss the general mechanism leading to long-range rapidity and angular correlations produced in high energy collisions (the "ridge"). This effect naturally appears in the high energy QCD and is strongly sensitive to physics of the gluon saturation. We comment on various recent practical realizations of the main idea, paying special attention to N_c counting and stress the relevance of Pomeron loops.

We calculate the ground state properties of recently synthesized superheavy elements (SHEs) from Z = 105–118 along with the predicted proton magic Z = 120. The relativistic and nonrelativistic mean field formalisms are used to evaluate the binding energy (BE), charge radius, quadrupole deformation parameter and the density distribution of nucleons. We analyzed the stability of the nuclei based on BE and neutron to proton ratio. We also studied the bubble structure which reveals the special features of the superheavy nuclei.

A model is proposed in which the presently existing elementary particles are the result of an evolution proceeding from the simplest possible particle state to successively more complex states via a series of symmetry-breaking transitions. The properties of two fossil particles — the tauon and muon — together with the observed photon–baryon number ratio provide information that makes it possible to track the early development of particles. A computer simulation of the evolution reveals details about the purpose and history of all presently known elementary particles. In particular, it is concluded that the heavy Higgs particle that generates the bulk of the mass of the Z and W bosons also comes in a light version, which generates small mass contributions to the charged leptons. The predicted mass of this "flyweight" Higgs boson is 0.505 MeV/c², 106.086 eV/c² or 12.0007 μeV/c² (corresponding to a photon of frequency 2.9018 GHz) depending on whether it is associated with the tauon, muon or electron. Support for the conclusion comes from the Brookhaven muon g-2 experiment, which indicates the existence of a Higgs particle lighter than the muon.

We suggest a particular procedure of derivation of the beta-stability line, the nuclear Coulomb energy and the isotopic symmetry energy. The approach is based on the analysis of the A-dependency of the shift of neutron–proton chemical potentials Δλ = λ_n-λ_p. We observe the nonmonotonic (sawtooth) shape of the β-stability line as a function of mass number A and establish the relation of local maxima of the β-stability line to the mass numbers of the double-closed shells. The behavior of the symmetry energy coefficient b_sym(A) at fixed neutron excess Y = N-Z is analyzed. We show that, qualitatively, b_sym(A) has canyon-like behavior for a given value of Y. The width and the position of the bottom of such "canyon" depend on neutron excess.

The effects of viscosity on the space-time evolution of quark gluon plasma produced in nuclear collisions at relativistic heavy ion collider energies have been studied. The entropy generated due to the viscous motion of the fluid has been taken into account in constraining the initial temperature by the final multiplicity (measured at the freeze-out point). The viscous effects on the photon spectra has been introduced consistently through the evolution dynamics and phase space factors of all the participating partons/hadrons in the production process. In contrast to some of the recent calculations the present work includes the contribution from the hadronic phase. A small change in the transverse momentum (p_T) distribution of photons is observed due to viscous effects.

We study the nuclear reaction cross-sections for some of the neutron-rich nuclei in the lighter mass region of the periodic chart which are recently measured. The well-known Glauber formalism is used by taking deformed relativistic and nonrelativistic densities as input in the calculations. We find reasonable reaction cross-sections with both the densities. However with a better inspection of the results, it is noticed that the results obtained with relativistic densities are more closure to the experimental data than the nonrelativistic Skyrme densities.

The nuclear potential energies of neutron deficient even–even rare earth nuclei ¹⁵⁸Er and ¹⁶²Hf for the spin range 0–60 are computed within the framework of cranked Nilsson–Strutinsky shell correction method. The potential energy surface diagrams are analyzed in terms of quadrupole deformation and triaxiality parameter. The shape evolution of these isotopes with respect to spin is studied. The spin dependence of nuclear equilibrium potential energy is also verified.