Pressure effect in the X-ray intrinsic position resolution in noble gases and mixtures

A study of the gas pressure effect in the position resolution of an interacting X- or gamma-ray photon in a gas medium is performed. The intrinsic position resolution for pure noble gases (Argon and Xenon) and their mixtures with CO2 and CH4 were calculated for several gas pressures (1-10bar) and for photon energies between 5.4 and 60.0 keV, being possible to establish a linear match between the intrinsic position resolution and the inverse of the gas pressure in that energy range. In order to evaluate the quality of the method here described, a comparison between the available experimental data and the calculated one in this work, is done and discussed. In the majority of the cases, a strong agreement is observed

CP tests of Higgs couplings in t¯th semileptonic events at the LHC

The CP nature of the Higgs coupling to top quarks is addressed in this paper, in single charged lepton final states of t¯th events produced in proton-proton collisions at the LHC. Pure scalar (h=H) and pseudoscalar (h=A) Higgs boson signal events, generated with MadGraph5_aMC@NLO, are fully reconstructed using a kinematic fit. Angular distributions of the decay products, as well as CP-sensitive asymmetries, are exploited to separate and gain sensitivity to possible pseudoscalar components of the Higgs boson and reduce the contribution from the dominant irreducible background t¯tb¯b. Significant differences are found between the pure CP-even and -odd signal hypotheses as well as with respect to the Standard Model background, in particular the t¯tb¯b contribution. Such differences survive the event reconstruction, allowing one to define optimal observables to extract the Higgs couplings parameters from a global fit. A dedicated analysis is applied to efficiently identify signal events and reject as much as possible the expected Standard Model background. The results obtained are compared with a similar analysis in the dilepton channel. We show that the single lepton channel is more promising overall and can be used in combination to study the CP nature of the Higgs coupling to top quarks.We would like to thank S. Amor Dos Santos et al. for providing the angular distributions from their analysis in the dileptonic channel [17,18]. This work was partially supported by Fundacao para a Ciencia e Tecnologia (Projects No. CERN/FIS-NUC/0005/2015 and No. CERN/FP/123619/2011, Grant No. SFRH/BPD/100379/2014, and Contract No. IF/01589/2012/CP0180/CT0002). Special thanks goes to our long-term collaborator Filipe Veloso for the invaluable help and availability on the evaluation of the confidence limits discussed in this paper.info:eu-repo/semantics/publishedVersio

The Resistive-Plate WELL with Argon mixtures - a robust gaseous radiation detector

A thin single-element THGEM-based, Resistive-Plate WELL (RPWELL) detector was operated with 150 GeV/c muon and pion beams in Ne/(5%CH$_4$), Ar/(5%CH$_4$) and Ar/(7%CO$_2$); signals were recorded with 1 cm$^2$ square pads and SRS/APV25 electronics. Detection efficiency values greater than 98% were reached in all the gas mixtures, at average pad multiplicity of 1.2. The use of the 10$^9${\Omega}cm resistive plate resulted in a completely discharge-free operation also in intense pion beams. The efficiency remained essentially constant at 98-99% up to fluxes of $\sim$10$^4$Hz/cm$^2$, dropping by a few % when approaching 10$^5$ Hz/cm$^2$. These results pave the way towards cost-effective, robust, efficient, large-scale detectors for a variety of applications in future particle, astro-particle and applied fields. A potential target application is digital hadron calorimetry.Comment: presented at the 2016 VIenna Conf. On instrumentation. Submitted to the Conference proceeding

Shame and psychopathology. Its role in the genesis and perpetuation of different disorders

publishersversionpublishe

Fighting or supporting corruption? The role of public sector audit organizations in Brazil

Public sector audit organizations are usually expected to fight corruption. Yet they may also end up being involved in, and contributing to, sustaining corruption. Relying on multiple interviews, this paper sheds new light on the concrete mechanisms through which corruption is sustained by Brazilian regional Courts of Accounts and their members. Our findings show how politico-economic elites’ private interests infiltrate the Courts via the appointment of high-ranked officials and how those officials may resort to a variety of actions to perpetrate forms of selective justice and to weaken the audit findings of these organizations – which ends up strengthening and supporting corruption. Additionally, we provide evidence of collective action emerging to challenge the current situation and reinforce the role Courts could play as watchdogs of the public interest. We contribute to the literature by highlighting the deleterious role of the interface between political and economic interests and the functioning of audit organizations. Moreover, relying on the literature of first- and second-order corruption, we discuss the specific conditions and mechanisms which enable corruption in public audit organizations. Finally, we present practical implications providing alternative views to the status quo

A dynamic method for charging-up calculations: the case of GEM

The simulation of Micro Pattern Gaseous Detectors (MPGDs) signal response is an important and powerful tool for the design and optimization of such detectors. However, several attempts to simulate exactly the effective charge gain have not been completely successful. Namely, the gain stability over time has not been fully understood. Charging-up of the insulator surfaces have been pointed as one of the responsible for the difference between experimental and Monte Carlo results. This work describes two iterative methods to simulate the charging-up in one MPGD device, the Gas Electron Multiplier (GEM). The first method uses a constant step for avalanches time evolution, very detailed, but slower to compute. The second method uses a dynamic step that improves the computing time. Good agreement between both methods was reached. Despite of comparison with experimental results shows that charging-up plays an important role in detectors operation, should not be the only responsible for the difference between simulated and measured effective gain, but explains the time evolution in the effective gain.Comment: Minor changes in grammatical statements and inclusion of some important information about experimental setup at section "Comparison with experimental results

First in-beam studies of a Resistive-Plate WELL gaseous multiplier

We present the results of the first in-beam studies of a medium size (10$\times$10 cm$^2$) Resistive-Plate WELL (RPWELL): a single-sided THGEM coupled to a pad anode through a resistive layer of high bulk resistivity ($\sim$10$^9 \Omega$cm). The 6.2~mm thick (excluding readout electronics) single-stage detector was studied with 150~GeV muons and pions. Signals were recorded from 1$\times$1 cm$^2$ square copper pads with APV25-SRS readout electronics. The single-element detector was operated in Ne\(5% $\mathrm{CH_{4}}$) at a gas gain of a few times 10$^4$, reaching 99$\%$ detection efficiency at average pad multiplicity of $\sim$1.2. Operation at particle fluxes up to $\sim$10$^4$ Hz/cm$^2$ resulted in $\sim$23$\%$ gain drop leading to $\sim$5$\%$ efficiency loss. The striking feature was the discharge-free operation, also in intense pion beams. These results pave the way towards robust, efficient large-scale detectors for applications requiring economic solutions at moderate spatial and energy resolutions.Comment: Accepted by JINS

Genotypic selection of advanced potato clones by REML/BLUP.

<div><p>ABSTRACT Potato genotypes were evaluated in their performance, according to the genotype values for tuber yield traits. The experiments were carried out in Canoinhas and Pelotas, Brazil, in spring 2014. Eleven advanced clones and two commercial cultivars (Agata and Asterix) (check cultivars) were evaluated. A randomized complete block design with four replicates was used. Plots were harvested 110 days after planting, and evaluated for tuber yield components. The data were submitted to joint deviance analyzes using the REML/BLUP method. Clones F102-22-07 and F32-02-06 stood out positively for tuber yield. F102-22-07 showed high marketable tuber yield and average tuber weight, while clone F32-02-06 exhibited high marketable and total tuber yield. The superiority of these advanced clones in relation to the check cultivars, suggests their potential to be evaluated in other environments, aiming their release as new cultivars.</p></div