On the Special Significance of the Latest PAMELA Results in Astroparticle Physics

In continuation of their earlier measurements, the PAMELA group reported data on antiproton flux and $\bar{P}/P$ ratios in 2010 at much higher energies. In past we had dealt with these specific aspects of PAMELA data in great detail and each time we captured the contemporary data-trends quite successfully with the help of a multiple production model of secondary antiprotons with some non-standard ilk and with some other absolutely standard assumptions and approximations. In this work we aim at presenting a comprehensive and valid description of all the available data on antiproton flux and the nature of $\bar{P}/P$ ratios at the highest energies reported so far by the PAMELA experiment in 2010. The main physical implication of all this would, in the end, be highlighted.Comment: 8 pages, 6 figure

The L1 L^1 -Liouville property on graphs

In this paper we investigate the $L^1$-Liouville property, underlining its connection with stochastic completeness and other structural features of the graph. We give a characterization of the $L^1$-Liouville property in terms of the Green function of the graph and use it to prove its equivalence with stochastic completeness on model graphs. Moreover, we show that there exist stochastically incomplete graphs which satisfy the $L^1$-Liouville property and prove some comparison theorems for general graphs based on inner-outer curvatures. We also introduce the Dirichlet $L^1$-Liouville property of subgraphs and prove that if a graph has a Dirichlet $L^1$-Liouville subgraph, then it is $L^1$-Liouville itself. As a consequence, we obtain that the $L^1$-Liouville property is not affected by a finite perturbation of the graph and, just as in the continuous setting, a graph is $L^1$-Liouville provided that at least one of its ends is Dirichlet $L^1$-Liouville

Spatial Resolution of Double-Sided Silicon Microstrip Detectors for the PAMELA Apparatus

The PAMELA apparatus has been assembled and it is ready to be launched in a satellite mission to study mainly the antiparticle component of cosmic rays. In this paper the performances obtained for the silicon microstrip detectors used in the magnetic spectrometer are presented. This subdetector reconstructs the curvature of a charged particle in the magnetic field produced by a permanent magnet and consequently determines momentum and charge sign, thanks to a very good accuracy in the position measurements (better than 3 um in the bending coordinate). A complete simulation of the silicon microstrip detectors has been developed in order to investigate in great detail the sensor's characteristics. Simulated events have been then compared with data gathered from minimum ionizing particle (MIP) beams during the last years in order to tune free parameters of the simulation. Finally some either widely used or original position finding algorithms, designed for such kind of detectors, have been applied to events with different incidence angles. As a result of the analysis, a method of impact point reconstruction can be chosen, depending on both the particle's incidence angle and the cluster multiplicity, so as to maximize the capability of the spectrometer in antiparticle tagging.Comment: 28 pages, 18 figures, submitted to Nuclear Instruments and Methods in Physics Research

Databases for Researching Athletic Training Literature

Searching the athletic training literature can be confusing and overwhelming with many possible databases for locating relevant peer-reviewed scholarship. Finding evidence-based literature from respected publications is helpful in clinical decision-making for athletic training practitioners. This column details recommended databases and search tips to help students, staff, clinicians, and faculty in the field of athletic training find the literature they need to help make evidence-based decisions and to stay current with the published literature. Databases discussed include Cochrane, PubMed, SPORTDiscus, CINAHL, PEDro, Sports Medicine, and Education Index (formerly Physical Education Index), and Google Scholar

Academic Libraries and Athletic Training: Research Preferences of Athletic Training Students

To ensure academic standards are met for athletic training curriculums, it is essential that librarians and faculty understand student research habits and information literacy instruction preferences. This article provides results from a survey of undergraduate athletic training students conducted at two universities. Athletic training students prefer information literacy instruction at the beginning of the semester. When seeking research assistance, students ask their classmates first, followed by friends and Google. Most students spend up to 60 minutes researching online before seeking assistance and prefer in-person communication for assistance from the library followed by email

The Top Window for dark matter

We investigate a scenario that the top quark is the only window to the dark matter particle. We use the effective Lagrangian approach to write down the interaction between the top quark and the dark matter particle. Requiring the dark matter satisfying the relic density we obtain the size of the effective interaction. We show that the scenario can be made consistent with the direct and indirect detection experiments by adjusting the size of the effective coupling. Finally, we calculate the production cross section for $t\bar t + \chi \bar \chi$ at the Large Hadron Collider (LHC), which will give rise to an interesting signature of a top-pair plus large missing energy.Comment: 17 pages including 8 figures; added references and a footnot

The First Year of the Large Hadron Collider: A Brief Review

The first year of LHC data taking provided an integrated luminosity of about 35/pb in proton-proton collisions at sqrt(s)=7 TeV. The accelerator and the experiments have demonstrated an excellent performance. The experiments have obtained important physics results in many areas, ranging from tests of the Standard Model to searches for new particles. Among other results the physics highlights have been the measurements of the W-, Z-boson and t t-bar production cross-sections, improved limits on supersymmetric and other hypothetical particles and the observation of jet-quenching, elliptical flow and J/Psi suppression in lead-lead collisions at sqrt(sNN) = 2.76 TeV.Comment: 11 pages, 9 figures, invited brief review for Mod. Phys. Lett.

The Visible and Near Infrared module of EChO

The Visible and Near Infrared (VNIR) is one of the modules of EChO, the Exoplanets Characterization Observatory proposed to ESA for an M-class mission. EChO is aimed to observe planets while transiting by their suns. Then the instrument had to be designed to assure a high efficiency over the whole spectral range. In fact, it has to be able to observe stars with an apparent magnitude Mv= 9-12 and to see contrasts of the order of 10-4 - 10-5 necessary to reveal the characteristics of the atmospheres of the exoplanets under investigation. VNIR is a spectrometer in a cross-dispersed configuration, covering the 0.4-2.5 micron spectral range with a resolving power of about 330 and a field of view of 2 arcsec. It is functionally split into two channels respectively working in the 0.4-1 and 1.0-2.5 micron spectral ranges. Such a solution is imposed by the fact the light at short wavelengths has to be shared with the EChO Fine Guiding System (FGS) devoted to the pointing of the stars under observation. The spectrometer makes use of a HgCdTe detector of 512 by 512 pixels, 18 micron pitch and working at a temperature of 45K as the entire VNIR optical bench. The instrument has been interfaced to the telescope optics by two optical fibers, one per channel, to assure an easier coupling and an easier colocation of the instrument inside the EChO optical bench.Comment: 26 page