A new method for the solution of the Schrodinger equation

We present a new method for the solution of the Schrodinger equation applicable to problems of non-perturbative nature. The method works by identifying three different scales in the problem, which then are treated independently: An asymptotic scale, which depends uniquely on the form of the potential at large distances; an intermediate scale, still characterized by an exponential decay of the wave function and, finally, a short distance scale, in which the wave function is sizable. The key feature of our method is the introduction of an arbitrary parameter in the last two scales, which is then used to optimize a perturbative expansion in a suitable parameter. We apply the method to the quantum anharmonic oscillator and find excellent results.Comment: 4 pages, 4 figures, RevTex

Study of the lepton flavor-violating Z′→τμZ'\to\tau\mu decay

The lepton flavor violating $Z^{\prime}\to\tau\mu$ decay is studied in the context of several extended models that predict the existence of the new gauge boson named $Z^\prime$. A calculation of the strength of the lepton flavor violating $Z^\prime\mu\tau$ coupling is presented by using the most general renormalizable Lagrangian that includes lepton flavor violation. We used the experimental value of the muon magnetic dipole moment to bound this coupling, from which the $\mathrm{Re}(\Omega_{L\mu\tau}\Omega^\ast_{R\mu\tau})$ parameter is constrained and it is found that $\mathrm{Re}(\Omega_{L\mu\tau}\Omega^\ast_{R\mu\tau})\sim 10^{-2}$ for a $Z^\prime$ boson mass of 2 TeV. Alongside, we employed the experimental restrictions over the $\tau\to\mu\gamma$ and $\tau\to\mu\mu^+\mu^-$ processes in the context of several models that predict the existence of the $Z^\prime$ gauge boson to bound the mentioned coupling. The most restrictive bounds come from the calculation of the three-body decay. For this case, it was found that the most restrictive result is provided by a vector-like coupling, denoted as $|\Omega_{\mu\tau}|^2$, for the $Z_\chi$ case, finding around $10^{-2}$ for a $Z^\prime$ boson mass of 2 TeV. We used this information to estimate the branching ratio for the $Z^\prime\to\tau\mu$ decay. According to the analyzed models the least optimistic result is provided by the Sequential $Z$ model, which is of the order of $10^{-2}$ for a $Z^\prime$ boson mass around 2 TeV.Comment: Revised versio

STRATEGy Seismic neTwoRk/Array in norThwEstern arGentina: Study of the 2015 El Galpón earthquake and its aftershock sequence

After a damaging, medium-sized earthquake (Mw 5.8; October 17, 2015) in El Galpón area in the Salta Province, we installed a local seismological network around the estimated epicenter covering also remarkable tectonic and geological orographic structures. The 2015 earthquake took place in the Andean foreland at about 17km depth. The so called Santa Bárbara System is the easternmost morphostructural region of the central Andes. As a part of the broken foreland it is bounded to the north by the Subandean Belt and the Sierras Pampeanas lying in the south; to the east joins the Chaco-Paraná basin.Eje: Estudio del Interior Terrestre.Facultad de Ciencias Astronómicas y Geofísica

STRATEGy Seismic neTwoRk/Array in norThwEstern arGentina: Study of the 2015 El Galpón earthquake and its aftershock sequence

After a damaging, medium-sized earthquake (Mw 5.8; October 17, 2015) in El Galpón area in the Salta Province, we installed a local seismological network around the estimated epicenter covering also remarkable tectonic and geological orographic structures. The 2015 earthquake took place in the Andean foreland at about 17km depth. The so called Santa Bárbara System is the easternmost morphostructural region of the central Andes. As a part of the broken foreland it is bounded to the north by the Subandean Belt and the Sierras Pampeanas lying in the south; to the east joins the Chaco-Paraná basin.Eje: Estudio del Interior Terrestre.Facultad de Ciencias Astronómicas y Geofísica

Candida bracarensis, an emerging yeast involved in human infections

Sir, Invasive candidiasis is an increasingly detected complication in hospitalized adult patients, due to an increase in patients at risk (patients admitted to intensive care units, post-surgical patients, neutropenic and immunosuppressed patients). Non- albicans Candida species have increased in multiple centers and new species are proposed. This is the case of Candida nivariensis and Candida bracarensis that are phylogenetically related with C. glabrata, although with sufficiently genotypically different to justify their assignment as separate species..

The prolate-to-oblate shape transition of phospholipid vesicles in response to frequency variation of an AC electric field can be explained by the dielectric anisotropy of a phospholipid bilayer

The external electric field deforms flaccid phospholipid vesicles into spheroidal bodies, with the rotational axis aligned with its direction. Deformation is frequency dependent: in the low frequency range (~ 1 kHz), the deformation is typically prolate, while increasing the frequency to the 10 kHz range changes the deformation to oblate. We attempt to explain this behaviour with a theoretical model, based on the minimization of the total free energy of the vesicle. The energy terms taken into account include the membrane bending energy and the energy of the electric field. The latter is calculated from the electric field via the Maxwell stress tensor, where the membrane is modelled as anisotropic lossy dielectric. Vesicle deformation in response to varying frequency is calculated numerically. Using a series expansion, we also derive a simplified expression for the deformation, which retains the frequency dependence of the exact expression and may provide a better substitute for the series expansion used by Winterhalter and Helfrich, which was found to be valid only in the limit of low frequencies. The model with the anisotropic membrane permittivity imposes two constraints on the values of material constants: tangential component of dielectric permittivity tensor of the phospholipid membrane must exceed its radial component by approximately a factor of 3; and the membrane conductivity has to be relatively high, approximately one tenth of the conductivity of the external aqueous medium.Comment: 17 pages, 6 figures; accepted for publication in J. Phys.: Condens. Matte