Modern Physics Letters A

A model of lepton flavor symmetry is discussed, using the non-Abelian finite group T₇ and the gauging of B-L, which has a residual Z₃ symmetry in the charged-lepton Yukawa sector, allowing it to be observable at the Large Hadron Collider (LHC) from the decay of the new Z' gauge boson of this model to a pair of scalar bosons which have the unusual highly distinguishable final states τ^- τ^- μ⁺ e⁺.

Inclusion of f(R) term in the action of Hořava–Lifshitz quantum gravity with projectability but without detailed balance condition is investigated, where R denotes the 3-spatial dimensional Ricci scalar. Conditions for the spin-0 graviton to be free of ghosts and instability are studied. The requirement that the theory reduces to general relativity in the IR makes the scalar mode unstable in the Minkowski background but stable in the de Sitter. It is remarkable that the dark sector, dark matter and dark energy, of the universe has a naturally geometric origin in such a setup. Bouncing universes can also be constructed. Scalar perturbations in the FRW backgrounds with nonzero curvature are also studied.

We investigate the motion of a magnetized particle orbiting around a black hole in braneworld immersed in asymptotically uniform magnetic field. The influence of brane parameter on effective potential of the radial motion of magnetized spinning particle around the braneworld black hole using Hamilton–Jacobi formalism is studied. It is found that circular orbits for photons and slowly moving particles may become stable near r = 3M. It was argued that the radii of the innermost stable circular orbits are sensitive on the change of brane parameter. Similar discussion without Weil parameter has been considered by de Felice et al. in Refs. 1 and 2.

We consider Friedberg–Lee–Sirlin Q-balls in a (3+1)-dimensional model with vanishing scalar potential of one of the fields. We show that, unlike in (2+1) and (1+1) dimensions, the Q-ball is stabilized by the gradient energy of this field and carries scalar charge, over and beyond the global charge. The latter property is also inherent in a model with the scalar potential that does not vanish in a finite field region near the origin.

In the torsion ⊗ curvature approach of gravity Chern–Simons modification has been considered here. It has been found that Chern–Simons contribution to the Bianchi identity cancels from that of the scalar field part. But "homogeneity and isotropy" consideration of present day cosmology is a consequence of the "strong equivalence principle" and vice versa.

Global fits to neutrino oscillation data are compatible with tri-bimaximal mixing pattern, which predict θ₂₃ = π/4, and θ₁₃ = 0. We propose here to parametrize the tri-bimaximal mixing matrix V_TBM by its hermitian generator H_TBM using the exponential map. Then we use the exponential map to express the deviations from tri-bimaximal pattern by deriving the hermitian matrices H_{z = 0} and H₁. These deviations might come from the symmetry breaking of the neutrino and charged lepton sectors.

The quantum H₄ integrable system is a 4D system with rational potential related to the non-crystallographic root system H₄ with 600-cell symmetry. It is shown that the gauge-rotated H₄ Hamiltonian as well as one of the integrals, when written in terms of the invariants of the Coxeter group H₄, is in algebraic form: it has polynomial coefficients in front of the derivatives. Any eigenfunction is a polynomial multiplied by ground-state function (factorization property). Spectra correspond to one of the anisotropic harmonic oscillators. The Hamiltonian has infinitely-many finite-dimensional invariant subspaces in polynomials, they form the infinite flag with the characteristic vector α = (1, 5, 8, 12).

Angular distributions of fragments have been studied for ¹⁹⁷Au +¹⁹⁷Au ternary reactions at bombarding energy 15 A MeV by an improved quantum molecular dynamics model. The calculated results are qualitatively in agreement with the experimental data. Through analyzing the angular distributions of fragments, it is shown that in semi-peripheral collisions ¹⁹⁷Au+¹⁹⁷Au interacting system often reseparates into three massive fragments which are almost aligned in space along the separation axis. The anisotropic distribution in azimuthal angle ϕ shows that the projectile-like fragment (PLF) or target-like fragment (TLF) breaks up violently, reflecting nonequilibrium effects in the consecutive reseparation. The time scale elapsing from the scission of the binary PLF+TLF system to the secondary scission of PLF or TLF is estimated to be of about 80 fm/c. It is found that the distribution in Θ_cm depends on the impact parameter, and its peak seems to be moving and narrowing with increasing impact parameter. Its asymptotic peak value is in agreement with the grazing angle. The shift of the peak value of Θ_cm implies that the collective energy dissipation depends on impact parameter and decreases with impact parameter increasing since the exchange of nucleons becomes less frequent during the reaction process.