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The present work is aimed at considering the recent forms of Bohr Hamiltonian, which are namely the hybrid model and the model combining the X(3) and E(5) symmetries, in the presence of the β-dependent Morse potential. The energy spectra and the transition rates of each model have been obtained. Some nuclei, the isotopes of Ru, Pd, Xe and 134Ba, have been fitted by using the three-parameter solution of the combined Hamiltonian with the Morse potential. Also, a few nuclei have been fitted by using the four-parameter solution of the hybrid model. In order to evaluate our results, in addition to reporting the root mean square (rms), we compare our data for each nucleus with the corresponding results of other references. [ABSTRACT FROM AUTHOR]

In this work, we investigate the -rigid version of Bohr-Hamiltonian for the modified Davidson potential. Since the corresponding wave equation cannot be solved analytically, we apply the variational method. The related wave function, energy spectra and transition rates are determined. In order to evaluate our results, we fit the formula for the energy spectra to the available experimental data for some nuclei and compare the obtained standard error with the corresponding one in other similar work. Moreover, we study the collective behavior of these nuclei through the evolution of two quantities and in terms of number of valence nucleons. [ABSTRACT FROM AUTHOR]

In this paper, the wave equation corresponding to the -rigid version of Bohr Hamiltonian for the modified Davidson potential is investigated in the position-dependent mass formalism. By solving the related differential equation, the wave function, energy spectra and transition rates are obtained. In order to evaluate our results, they are compared with experimental data through the standard error. [ABSTRACT FROM AUTHOR]

We determine the energy eigenvalues and eigenstates of the Bohr Hamiltonian for -rigid prolate nuclei with the Coulomb-like potential in minimal length formalism. We first show corresponding Hamiltonian of -rigid prolate nuclei then investigate the effects of minimal length parameter in energy levels and obtain the transition rates. Ordinary results are recovered for the vanishing minimal length parameter and for the clarity of our results, some instructive graphs have been prepared. [ABSTRACT FROM AUTHOR]

We determine the energy spectrum and wave function for the Bohr-Mottelson Hamiltonian on -rigid regime separately with the harmonic and Coulomb energy-dependent potentials. We study the effect of potential parameters on the energy levels and probability density distribution. The transition rates are determined in each case. [ABSTRACT FROM AUTHOR]

The Klein–Gordon and Dirac equations are considered in a semiinfinite laboratory (x > 0) in the presence of background metrics ds2 = u2(x)ημν dxμ dxν and ds2 = -dt2 + u2(x)ηij dxi dxj with u(x) = e±gx. These metrics have nonconstant scalar-curvatures. Various aspects of the solutions are studied. For the first metric with u(x) = egx, it is shown that the spectra are discrete, with the ground state energy $E^2_{\min} = p^2c^2 + g^2c^2\hbar^2$ for spin-0 particles. For u(x) = e-gx, the spectrums are found to be continuous. For the second metric with u(x) = e-gx, each particle, depends on its transverse-momentum, can have continuous or discrete spectrum. For Klein–Gordon particles, this threshold transverse-momentum is $\sqrt{3}g/2$, while for Dirac particles it is g/2. There is no solution for u(x) = egx case. Some geometrical properties of these metrics are also discussed. [ABSTRACT FROM AUTHOR]

We discuss the confining features of the Schwinger model on the Poincaré half plane. We show that despite the fact that the expectation value of the large Wilson loop of massless Schwinger model displays perimeter behavior, the system can be in confining phase due to the singularity of the metric at horizontal axis. It is also shown that in the quenched Schwinger model, the area dependence of the Wilson loop, in contrast to the flat case, is a not a sign of confinement and the model has a finite energy even for large external charges separation. The presence of dynamical fermions cannot modify the screening or the confining behavior of the system. Finally we show that in the massive Schwinger model, the system is again in screening phase. The zero curvature limit of the solutions is also discussed. [ABSTRACT FROM AUTHOR]

By generalizing the auxiliary field term in the Lagrangian of simplicial chiral models on a (d - 1)-dimensional simplex, the generalized simplicial chiral models has been introduced in Ref. 1. These models can be solved analytically only in d = 0 and d = 2 cases at large-N limit. In the d = 0 case, we calculate the eigenvalue density function in strong regime and show that the partition function computed from this density function is consistent with one calculated by path integration directly. In the d = 2 case, it is shown that all V = Tr(AA†)[sup n] models have a third order phase transition, the same as the two-dimensional Yang-Mills theory. [ABSTRACT FROM AUTHOR]

In the context of the Einstein-Cartan-Dirac model, where the torsion of the space-time couples to the axial currents of the fermions, we study the effects of this quantumgravitational interaction on a massless neutrino beam crossing through a medium with a high number density of fermions at rest. We calculate the reflection amplitude and show that a specific fraction of the incident neutrinos reflects from this potential if the polarization of the medium is different from zero. We also discuss the order of magnitude of the fermionic number density in which this phenomenon is observable, in other theoretical contexts, for example, the strong gravity regime and the effective field theory approach. [ABSTRACT FROM AUTHOR]

There have been some controversies about the large N behaviour of the 2-D Yang–Mills and chiral 2-D Yang–Mills theories. To be more specific, is there a one-parameter family of minima of the free energy in the strong region, or is the minimum unique? We show that by adding an equation (which was missing) to the known equations, the minimum becomes unique. [ABSTRACT FROM AUTHOR]

Using Einstein–Cartan–Dirac theory, we study the effect of torsion on neutrino oscillation. We see that torsion cannot induce neutrino oscillation, but affects it whenever oscillation exists for other reasons. We show that the torsion effect on neutrino oscillation is as important as the neutrino mass effect, whenever the ratio of neutrino number density to neutrino energy is ∼ 10[sup 69]cm[sup -3]/eV, or the number density of the matter is ∼ 10[sup 69]cm[sup -3]. [ABSTRACT FROM AUTHOR]