Neutrino Masses in Split Supersymmetry

We investigate the possibility to generate neutrino masses in the context of Split supersymmetric scenarios where all sfermions are very heavy. All relevant contributions coming from the R-parity violating terms to the neutrino mass matrix up to one-loop level are computed, showing the importance of the Higgs one-loop corrections. We conclude that it is not possible to generate all neutrino masses and mixings in Split SUSY with bilinear R-Parity violating interactions. In the case of Partial Split SUSY the one-loop Higgs contributions are enough to generate the neutrino masses and mixings in agreement with the experiment. In the context of minimal SUSY SU(5) we find new contributions which help us to generate neutrino masses in the case of Split SUSY.Comment: 33 pages, 6 figures, to appear in Physical Review

Effects of anisotropy in a nonlinear crystal for squeezed vacuum generation

Squeezed vacuum (SV) can be obtained by an optical parametric amplifier (OPA) with the quantum vacuum state at the input. We are interested in a degenerate type-I OPA based on parametric down-conversion (PDC) where due to phase matching requirements, an extraordinary polarized pump must impinge onto a birefringent crystal with a large \chi(2) nonlinearity. As a consequence of the optical anisotropy of the medium, the direction of propagation of the pump wavevector does not coincide with the direction of propagation of its energy, an effect known as transverse walk-off. For certain pump sizes and crystal lengths, the transverse walk-off has a strong influence on the spatial spectrum of the generated radiation, which in turn affects the outcome of any experiment in which this radiation is employed. In this work we propose a method that reduces the distortions of the two-photon amplitude (TPA) of the states considered, by using at least two consecutive crystals instead of one. We show that after anisotropy compensation the TPA becomes symmetric, allowing for a simple Schmidt expansion, a procedure that in practice requires states that come from experimental systems free of anisotropy effects

High-order harmonic generation driven by chirped laser pulses induced by linear and non linear phenomena

We present a theoretical study of high-order harmonic generation (HHG) driven by ultrashort optical pulses with different kind of chirps. The goal of the present work is perform a detailed study to clarify the relevant parameters in the chirped pulses to achieve a noticeable cut-off extensions in HHG. These chirped pulses are generated using both linear and nonlinear dispersive media.The description of the origin of the physical mechanisms responsible of this extension is, however, not usually reported with enough detail in the literature. The study of the behaviour of the harmonic cut-off with these kind of pulses is carried out in the classical context, by the integration of the Newton-Lorentz equation complemented with the quantum approach, based on the integration of the time dependent Schr\"odinger equation in full dimensions (TDSE-3D), we are able to understand the underlying physics.Comment: 13 pages, 8 figure

Asteroseismology of delta Scuti stars in open clusters: Praesepe

The present paper provides a general overview of the asteroseismic potential of delta Scuti stars in clusters, in particular focusing on convection diagnostics. We give a summarise of the last results obtained by the authors for the Praesepe cluster of which five delta Scuti stars are analysed. In that work, linear analysis is confronted with observations, using refined descriptions for the effects of rotation on the determination of the global stellar parameters and on the adiabatic oscillation frequency computations. A single, complete, and coherent solution for all the selected stars is found, which lead the authors to find important restrictions to the convection description for a certain range of effective temperatures. Furthermore, the method used allowed to give an estimate of the global parameters of the selected stars and constrain the cluster.Comment: 6 pages, 1 figure. Accepted for publication in Communications in Asteroseismolog

When is Containment Decidable for Probabilistic Automata?

The containment problem for quantitative automata is the natural quantitative generalisation of the classical language inclusion problem for Boolean automata. We study it for probabilistic automata, where it is known to be undecidable in general. We restrict our study to the class of probabilistic automata with bounded ambiguity. There, we show decidability (subject to Schanuel's conjecture) when one of the automata is assumed to be unambiguous while the other one is allowed to be finitely ambiguous. Furthermore, we show that this is close to the most general decidable fragment of this problem by proving that it is already undecidable if one of the automata is allowed to be linearly ambiguous

Probing for Instanton Quarks with epsilon-Cooling

We use epsilon-cooling, adjusting at will the order a^2 corrections to the lattice action, to study the parameter space of instantons in the background of non-trivial holonomy and to determine the presence and nature of constituents with fractional topological charge at finite and zero temperature for SU(2). As an additional tool, zero temperature configurations were generated from those at finite temperature with well-separated constituents. This is achieved by "adiabatically" adjusting the anisotropic coupling used to implement finite temperature on a symmetric lattice. The action and topological charge density, as well as the Polyakov loop and chiral zero-modes are used to analyse these configurations. We also show how cooling histories themselves can reveal the presence of constituents with fractional topological charge. We comment on the interpretation of recent fermion zero-mode studies for thermalized ensembles at small temperatures.Comment: 26 pages, 14 figures in 33 part

Automated multi-paradigm analysis of extended and layered queueing models with LINE

LINE is an open source MATLAB library for performance and relia-bility analysis of systems that can be modeled by means of queueingtheory. Recently, a new major release of the tool (version 2.0.0) hasintroduced several novel features, which are the focus of this demon-stration. These include, among others, an object-oriented modelinglanguage aligned with the abstraction of the Java Modelling Tools( JMT) simulator and a set of native solvers based on state-of-the-artanalytical and simulation-based solution paradigms

Stable, metastable and unstable states in the mean-field RFIM at T=0

We compute the probability of finding metastable states at a given field in the mean-field random field Ising model at T=0. Remarkably, this probability is finite in the thermodynamic limit, even on the so-called ``unstable'' branch of the magnetization curve. This implies that the branch is reachable when the magnetization is controlled instead of the magnetic field, in contrast with the situation in the pure system.Comment: 10 pages, 3 figure