Modern Physics Letters A

A detailed investigation of the contribution from Coulomb effects to the observed mirror energy difference diagrams in nuclei in the lower part of the upper fp shell is presented by means of large-scale shell-model calculations.

The 2D Ricci flow equation in the conformal gauge is studied using the linearization approach. Using a nonlinear substitution of logarithmic type, the emergent quadratic equation is split in various ways. New special solutions involving arbitrary functions are presented. Some special reductions are also discussed.

Fermionic decays of the scalar leptoquarks , , S_m and of the scalar gluons F=F₁, F₂ predicted by the four-color symmetry model with the Higgs mechanism of the quark–lepton mass splitting are investigated. Widths and branching ratios of these decays are calculated and analyzed in dependence on coupling constants and on masses of the decaying particles. It is shown that the decays , , , , are dominant with the widths of order of a few GeV for m_S, m_F< 1 TeV and with the total branching ratios close to 1. In the case of m_S<m_t the dominant scalar leptoquark decays are , , , with the total branching ratios , and . A search for such decays at the LHC and Tevatron may be of interest.

We examine a generalized -symmetric quartic anharmonic oscillator model to determine the various physical variables perturbatively in powers of a small quantity ε. We make use of the Bender–Dunne operator basis elements and exploit the properties of the totally symmetric operator T_m,n.

By taking a Klein–Gordon field as the environment of a harmonic oscillator and using a new method for dealing with quantum dissipative systems (minimal coupling method), we find out the quantum dynamics and radiation reaction for a quantum damped harmonic oscillator. Applying perturbation method, we obtain some transition probabilities indicating the way energy flows between oscillator, reservoir and quantum vacuum.

We show that the seesaw neutrino mass mechanism can coexist naturally with an extended gauge symmetry (i.e. without any gauge hierarchy problem) provided that the gauge symmetry contains gauged lepton number differences. The simplest such "natural" seesaw models are constructed and their implications for neutrino anomalies discussed.

We study fermionic zero modes in the background of self-dual vortex on a two-dimensional non-compact extra space in 5+1 dimensions. In the Abelian Higgs model, we present a unified description of the topological and non-topological self-dual vortex on the extra two dimensions. Based on it, we study the localization of bulk fermions on a brane with the inclusion of Yang–Mills and gravity backgrounds in six dimensions. Through two simple cases, it is shown that the vortex background contributes a phase shift to the fermionic zero mode, this phase is actually origin from the Aharonov–Bohm effect.