Modern Physics Letters A

In this review, we summarize recent findings that show how standard 4D Einstein gravity coupled to a conformal field theory can become massive in anti de Sitter space. Key ingredients in this phenomenon are nonstandard "transparent" boundary condition given to the CFT fields and the fact that AdS space is not globally hyperbolic, due to the presence of a time-like boundary.

We reanalyze the constraints in neutrino masses and MNS lepton mixing parameters using the new data from the terrestrial (KamLAND) and astrophysical (WMAP) observations together with the Heidelberg–Moscow double beta decay experiment. It leads us to the almost degenerate or inverse hierarchy neutrino mass scenario. We discuss the possibility of getting the bound for the Majorana CP-violating phase.

The Landau–Zener effect is generalized for many-body systems with pairing residual interactions. The microscopic equations of motion are obtained and the ¹⁴C decay of ²²³Ra spectroscopic factors are deduced. An asymmetric nuclear shape parametrization given by two intersected spheres is used. The single particle level scheme is determined in the frame of the superasymmetric two-center shell model. The deformation energy is computed in the microscopic–macroscopic approximation. The penetrabilities are obtained within the WKB approximation. The fine structure of the cluster decay analyzed in the frame of this formalism gives a very good agreement with the experimental ratio of partial half-lives for transition to the first excited state and to the ground state.

By relating the Dirac neutrino mass matrix to the mass of the charged fermions and assuming that the product of the masses of the two lightest left-handed neutrinos is of the order of , we derive, within a leptogenesis scenario, a range of values for the mass of the heaviest right-handed neutrino, centered around the scale of B–L symmetry breaking in the SO(10) theory with Pati–Salam intermediate symmetry.

A new approach to the parametrization of the CKM matrix, V, is considered in which V is written as a linear combination of the unit matrix I and a nondiagonal matrix U which causes inter-generational-mixing, that is V = cos θ I + i sin θ U. Such a V depends on three real parameters including the parameter θ. It is interesting that a value of θ = π/4 is required to fit the available data on the CKM-matrix including CP-violation. Predictions of this fit for the angles α, β and γ for the unitarity triangle corresponding to , are given. For θ = π/4, we obtain α = 88.46°, β = 45.046° and γ = 46.5°. These values are just about in agreement, within errors, with the present data. It is very interesting that the unitarity triangle is expected to be approximately a right-angle, isosceles triangle. Our prediction sin 2β = 1 is in excellent agreement with the value 0.99 ± 0.15 ± 0.05 reported by the Belle collaboration at the Lepton–Photon 2001 meeting.

By use of the shock loading method, non-ideal SiO₂-aerogel plasmas with shock velocity up to 13 km/s and temperatures in the range of 1–2.5 eV have been generated. Temperatures were measured using fast pyrometry techniques and thermodynamic parameters measured and calculated were compared with results of a set of plasma models.

The classical Hamilton equations are reinterpreted by means of complex analysis, in a nonstandard way. This suggests a natural extension of the Hamilton equations to the quaternionic case, extension which coincides with the one introduced in Ref. 1 by a completely different approach.

In the minimal 3-3-1 model charged leptons come in a nondiagonal basis. Moreover, the Yukawa interactions of the model lead to a non-hermitian charged lepton mass matrix. In other words, the minimal 3-3-1 model presents a very complex lepton mixing. In view of this we check rigorously if the possible textures of the lepton mass matrices allowed by the minimal 3-3-1 model can lead or not to the neutrino mixing required by the recent experiments in neutrino oscillation.