Accurate Complex Scaling of Three Dimensional Numerical Potentials

The complex scaling method, which consists in continuing spatial coordinates into the complex plane, is a well-established method that allows to compute resonant eigenfunctions of the time-independent Schroedinger operator. Whenever it is desirable to apply the complex scaling to investigate resonances in physical systems defined on numerical discrete grids, the most direct approach relies on the application of a similarity transformation to the original, unscaled Hamiltonian. We show that such an approach can be conveniently implemented in the Daubechies wavelet basis set, featuring a very promising level of generality, high accuracy, and no need for artificial convergence parameters. Complex scaling of three dimensional numerical potentials can be efficiently and accurately performed. By carrying out an illustrative resonant state computation in the case of a one-dimensional model potential, we then show that our wavelet-based approach may disclose new exciting opportunities in the field of computational non-Hermitian quantum mechanics.Comment: 11 pages, 8 figure

Aplicación de indicadores cuali-cuantitativos para evaluar un programa de admisión a la educación superior

Las altas tasas de deserción observadas en los primeros años de la educación superior, podrían tener su origen en buena medida en dificultades de estudio generadas por insuficiencias en los conocimientos y capacidades adquiridas en las instancias educativas anteriores. Esto ha llevado a que buena parte de las instituciones implementen programas de admisión que, a través de cursos de nivelación, pretenden facilitar la inserción de los alumnos en la etapa universitaria. Sin embargo, si la proporción de alumnos ingresantes que no logran superarlos convenientemente es alta, dichos programas pueden llegar a entenderse como un obstáculo para el acceso a la educación superior. Las causas del mal desempeño de los ingresantes pueden ser diversas y no debe descartarse que entre ellas se encuentre un mal diseño de los cursos de nivelación. Los indicadores que en este trabajo se aplicarán intentarán por un lado cuantificar los resultados del programa a través del desempeño de los alumnos en el mismo, y por otro analizar cualitativamente, a través de la opinión de los alumnos, en que medida los cursos implementados cumplen con los objetivos del programa

Status of the Cylindical-GEM project for the KLOE-2 Inner Tracker

The status of the R&D on the Cylindrical-GEM (CGEM) detector foreseen as Inner Tracker for KLOE-2, the upgrade of the KLOE experiment at the DAFNE phi-factory, will be presented. The R&D includes several activities: i) the construction and complete characterization of the full-size CGEM prototype, equipped with 650 microns pitch 1-D longitudinal strips; ii) the study of the 2-D readout with XV patterned strips and operation in magnetic field (up to 1.5T), performed with small planar prototypes in a dedicated test at the H4-SPS beam facility; iii) the characterization of the single-mask GEM technology for the realization of large-area GEM foils.Comment: 4 pages, 10 figures, Presented at Vienna Conference on Instrumentation (Feb 15-20, 2010, Vienna, Austria). Submitted to the Proceeding

A Cylindrical GEM Inner Tracker for the BESIII experiment at IHEP

The Beijing Electron Spectrometer III (BESIII) is a multipurpose detector that collects data provided by the collision in the Beijing Electron Positron Collider II (BEPCII), hosted at the Institute of High Energy Physics of Beijing. Since the beginning of its operation, BESIII has collected the world largest sample of J/{\psi} and {\psi}(2s). Due to the increase of the luminosity up to its nominal value of 10^33 cm-2 s-1 and aging effect, the MDC decreases its efficiency in the first layers up to 35% with respect to the value in 2014. Since BESIII has to take data up to 2022 with the chance to continue up to 2027, the Italian collaboration proposed to replace the inner part of the MDC with three independent layers of Cylindrical triple-GEM (CGEM). The CGEM-IT project will deploy several new features and innovation with respect the other current GEM based detector: the {\mu}TPC and analog readout, with time and charge measurements will allow to reach the 130 {\mu}m spatial resolution in 1 T magnetic field requested by the BESIII collaboration. In this proceeding, an update of the status of the project will be presented, with a particular focus on the results with planar and cylindrical prototypes with test beams data. These results are beyond the state of the art for GEM technology in magnetic field

Performance of the cylindrical-GEM prototype for the inner tracker of KLOE-2

We developed a low mass, fully cylindrical and dead-zone-free GEM detector as inner tracker for the KLOE experiment upgrade at the DAFNE Φ-factory. The proposed detector, that opens the way for a new and competitive category of ultra-light, full sensitive vertex detectors for high energy physics experiments, will play a crucial role in the study of the K S and η rare decays and in the measurement of the neutral kaon interferometry. The main physics requirements are: good spatial resolutions, σ(rφ) = 200 µm and σ(z) = 500 µm and a very low material budget, 2% of X 0 for the whole detector. The inner tracker will be composed by five layers of cylindrical triple-GEM detectors (CGEM), covering the space from the beam pipe to the inner wall of the KLOE Drift Chamber (from 150 mm to 250 mm radius). Each CGEM is realized inserting one into the other the required five cylindrical structures made of thin (50 µ m) polyimide foils: the cathode, the three GEMs and the anode readout. In order to avoid the use of support frames inside the sensitive volume, the cylindrical GEMs are mechanically stretched from their ends where annular fiberglass frames are glued. The final result is a very light detector: only 0.2% of X 0 per layer inside the active area. A full scale prototype (300 mm diameter, 360 mm length) of the first layer of the inner tracker has been successfully built and characterized under different experimental conditions. After a brief description of the construction procedure, the results of the extensive tests are presented

Particle Probe of Horava-Lifshitz Gravity

Kehagias-Sfetsos black hole in Ho\v{r}ava-Lifshitz gravity is probed through particle geodesics. Gravitational force of KS black hole becomes weaker than that of Schwarzschild around horizon and interior space. Particles can be always scattered or trapped in new closed orbits, unlike those falling forever in Schwarzschild black. The properties of null and timelike geodesics are classified with values of coupling constants. The precession rates of the orbits are evaluated. The time trajectories are also classified under different values of coupling constants for both null and timelike geodesics. Physical phenomena that may be observable are discussed.Comment: 10 pages, 8 figure

Unconventional Cosmology

I review two cosmological paradigms which are alternative to the current inflationary scenario. The first alternative is the "matter bounce", a non-singular bouncing cosmology with a matter-dominated phase of contraction. The second is an "emergent" scenario, which can be implemented in the context of "string gas cosmology". I will compare these scenarios with the inflationary one and demonstrate that all three lead to an approximately scale-invariant spectrum of cosmological perturbations.Comment: 45 pages, 10 figures; invited lectures at the 6th Aegean Summer School "Quantum Gravity and Quantum Cosmology", Chora, Naxos, Greece, Sept. 12 - 17 2012, to be publ. in the proceedings; these lecture notes form an updated version of arXiv:1003.1745 and arXiv:1103.227

PARSIFAL: a toolkit for triple-GEM parametrized simulation

PARSIFAL (PARametrized SImulation) is a tool which reproduces a triple-GEM detector full response to the passage of a charged particle, taking into account most of the involved physical effects. A triple-GEM is a gaseous detector that amplifies the primary ionization, generated by the incoming radiation interacting with the gas, through three amplification stages, providing position measurement with a resolution around 100 micron, energy resolution better than 20% and time resolution below 10 ns. Despite well known and robust software such as GARFIELD++ can simulate the electron propagation in gas and the interaction with the electric field, considering the avalanche formation and signal creation, they are CPU-time consuming. The necessity to reduce the processing time while maintaining the precision of a full simulation is the main driver of this work. PARSIFAL takes into account the main processes involved in the signal formation, starting from ionization, spatial and temporal diffusion, the effect of the magnetic field, if any, and GEM amplification properties. The induction of the signal and the electronics response are also present. PARSIFAL parameters are evaluated by means of GARFIELD++ simulations; the results of the simulation are compared to experimental data from testbeam and tuning factors are applied to improve the matching.Comment: submitted to JINS