Solar Mikheyev-Smirnov-Wolfenstein Effect with Three Generations of Neutrinos

Under the assumption that the density variation of the electrons can be approximated by an exponential function, the solar Mikheyev-Smirnov-Wolfenstein effect is treated for three generations of neutrinos. The generalized hypergeometric functions that result from the exact solution of this problem are studied in detail, and a method for their numerical evaluation is presented. This analysis plays a central role in the determination of neutrino masses, not only the differences of their squares, under the assumption of universal quark-lepton mixing.Comment: 22 pages, LaTeX, including 2 figure

On the Size of the Dark Side of the Solar Neutrino Parameter Space

We present an analysis of the MSW neutrino oscillation solutions of the solar neutrino problem in the framework of two-neutrino mixing in the enlarged parameter space $(\Delta m^2, \tan^2\theta)$ with $\theta \in (0,\frac{\pi}{2})$. Recently, it was pointed out that the allowed region of parameters from a fit to the measured total rates can extend to values $\theta \geq \frac{\pi}{4}$ (the so called ``dark side'') when higher confidence levels are allowed. The purpose of this letter is to reanalize the problem including all the solar neutrino data available, to discuss the dependence on the statistical criteria in the determination of the CL of the ``dark side'' and to extract the corresponding limits on the largest mixing allowed by the data. Our results show that when the Super-Kamiokande data on the zenith angle distribution of events and the spectrum information is included, the regions extend more into the dark side.Comment: 5 pages,latex file using RevTex. Two-layer aproximation for the Earth density replaced by numerical integration with PREM. Latest parametrization of the sun matter density (BP2000) is included. Misprints corrected. Conclusions unchanged. 5 postscript figures (bitmapped for compression). A full version of the paper can be found at http://ific.uv.es/~penya/papers/ To appear in Phys. Rev.

Deviation of Neutrino Mixing from Bi-maximal

We have studied how observables of the neutrino mixing matrix can link up with the ones in the quark sector. The deviation from the bi-maximal flavor mixing is parameterized using a 3 x 3 unitary matrix. The neutrino mixings are investigated supposing this unitary matrix to be hierarchical like the quark mixing matrix. We obtain the remarkable prediction |U_{e3}| >= 0.03 from the experimentally allowed range tan^2 theta_{sol} = 0.24 ~ 0.89. The CP violation in neutrino oscillations is expected to be very small.Comment: Some references are adde

Lepton Flavor Violating Process in Bi-maximal texture of Neutrino Mixings

We investigate the lepton flavor violation in the framework of the MSSM with right-handed neutrinos taking the large mixing angle MSW solution in the quasi-degenerate and the inverse-hierarchical neutrino masses. We predict the branching ratio of $\mu \to e+\gamma$ and $\tau \to \mu+\gamma$ processes assuming the degenerate right-handed Majorana neutrino masses. We find that the branching ratio in the quasi-degenerate neutrino mass spectrum is 100 times smaller than the ones in the inverse-hierarchical and the hierarchical neutrino spectra. We emphasize that the magnitude of $U_{e3}$ is one of important ingredients to predict BR($\mu \to e +\gamma$). The effect of the deviation from the complete-degenerate right-handed Majorana neutrino masses are also estimated. Furtheremore, we examine the S_{3\sL}\times S_{3\sR} model, which gives the quasi-degenerate neutrino masses, and the Shafi-Tavartkiladze model, which gives the inverse-hierarchical neutrino masses. Both predicted branching ratios of $\mu\to e+\gamma$ are smaller than the experimantal bound.Comment: Latex file, 38 pages, 10 figures, revised versio

Nuclear Skins and Halos in the Mean-Field Theory

Nuclei with large neutron-to-proton ratios have neutron skins, which manifest themselves in an excess of neutrons at distances greater than the radius of the proton distribution. In addition, some drip-line nuclei develop very extended halo structures. The neutron halo is a threshold effect; it appears when the valence neutrons occupy weakly bound orbits. In this study, nuclear skins and halos are analyzed within the self-consistent Skyrme-Hartree-Fock-Bogoliubov and relativistic Hartree-Bogoliubov theories for spherical shapes. It is demonstrated that skins, halos, and surface thickness can be analyzed in a model-independent way in terms of nucleonic density form factors. Such an analysis allows for defining a quantitative measure of the halo size. The systematic behavior of skins, halos, and surface thickness in even-even nuclei is discussed.Comment: 22 RevTeX pages, 22 EPS figures included, submitted to Physical Review

On the constraints violation in forward dynamics of multibody systems

It is known that the dynamic equations of motion for constrained mechanical multibody systems are frequently formulated using the Newton-Euler’s approach, which is augmented with the acceleration constraint equations. This formulation results in the establishment of a mixed set of partial differential and algebraic equations, which are solved in order to predict the dynamic behavior of general multibody systems. The classical resolution of the equations of motion is highly prone to constraints violation because the position and velocity constraint equations are not fulfilled. In this work, a general and comprehensive methodology to eliminate the constraints violation at the position and velocity levels is offered. The basic idea of the described approach is to add corrective terms to the position and velocity vectors with the intent to satisfy the corresponding kinematic constraint equations. These corrective terms are evaluated as function of the Moore-Penrose generalized inverse of the Jacobian matrix and of the kinematic constraint equations. The described methodology is embedded in the standard method to solve the equations of motion based on the technique of Lagrange multipliers. Finally, the effectiveness of the described methodology is demonstrated through the dynamic modeling and simulation of different planar and spatial multibody systems. The outcomes in terms of constraints violation at the position and velocity levels, conservation of the total energy and computational efficiency are analyzed and compared with those obtained with the standard Lagrange multipliers method, the Baumgarte stabilization method, the augmented Lagrangian formulation, the index-1 augmented Lagrangian and the coordinate partitioning method.The first author expresses his gratitude to the Portuguese Foundation for Science and Technology through the PhD grant (PD/BD/114154/2016). This work has been supported by the Portuguese Foundation for Science and Technology with the reference project UID/EEA/04436/2013, by FEDER funds through the COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI) with the reference project POCI-01-0145-FEDER-006941.info:eu-repo/semantics/publishedVersio

Blocking FSH induces thermogenic adipose tissue and reduces body fat

Functional Genomics of Systemic Disorder