Rio de Janeiro State University

About: Rio de Janeiro State University is a education organization based out in Rio de Janeiro, Brazil. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 16631 authors who have published 30919 publications receiving 465753 citations. The organization is also known as: UERJ & Rio de Janeiro State University.

Measurement of the cross section for top quark pair production in association with a W or Z boson in proton-proton collisions at √s = 13 TeV

Abstract: A measurement is performed of the cross section of top quark pair production in association with a W or Z boson using proton-proton collisions at a center-of-mass energy of 13 TeV at the LHC. The data sample corresponds to an integrated luminosity of 35.9 fb−1, collected by the CMS experiment in 2016. The measurement is performed in the same-sign dilepton, three- and four-lepton final states. The production cross sections are measured to be $$ \sigma \left(\mathrm{t}\overline{\mathrm{t}}\mathrm{W}\right)={0.77}_{-0.11}^{+0.12}{\left(\mathrm{stat}\right)}_{-0.12}^{+0.13}\left(\mathrm{syst}\right)\mathrm{p}\mathrm{b} $$ and $$ \sigma \left(\mathrm{t}\overline{\mathrm{t}}\mathrm{Z}\right)={0.99}_{-0.08}^{+0.09}{\left(\mathrm{stat}\right)}_{-0.10}^{+0.12}\left(\mathrm{syst}\right)\mathrm{p}\mathrm{b} $$ . The expected (observed) signal significance for the $$ \mathrm{t}\overline{\mathrm{t}}\mathrm{W} $$ production in same-sign dilepton channel is found to be 4.5 (5.3) standard deviations, while for the $$ \mathrm{t}\overline{\mathrm{t}}\mathrm{Z} $$ production in three- and four-lepton channels both the expected and the observed significances are found to be in excess of 5 standard deviations. The results are in agreement with the standard model predictions and are used to constrain the Wilson coefficients for eight dimension-six operators describing new interactions that would modify $$ \mathrm{t}\overline{\mathrm{t}}\mathrm{W} $$ and $$ \mathrm{t}\overline{\mathrm{t}}\mathrm{Z} $$ production.

Search for Signatures of Extra Dimensions in the Diphoton Mass Spectrum at the Large Hadron Collider

Abstract: A search for signatures of extra spatial dimensions in the diphoton invariant-mass spectrum has been performed with the CMS detector at the LHC. No excess of events above the standard model expectation is observed using a data sample collected in proton-proton collisions at √s=7 TeV corresponding to an integrated luminosity of 2.2 fb(-1). In the context of the large-extra-dimensions model, lower limits are set on the effective Planck scale in the range of 2.3-3.8 TeV at the 95% confidence level. These limits are the most restrictive bounds on virtual-graviton exchange to date. The most restrictive lower limits to date are also set on the mass of the first graviton excitation in the Randall-Sundrum model in the range of 0.86-1.84 TeV, for values of the associated coupling parameter between 0.01 and 0.10.

Entre as tramas da sexualidade brasileira

Abstract: This article is about sexual myths and conducts, aiming to demonstrate the constructed nature of the Brazilian sexuality representation as highly eroticized and malleable. Starting from a constructivist perspective of sexuality, the myth of Brazilian sexual nature is analyzed. There is a widespread idea that Brazilian culture is sexually too open, expansive and warm - which is considered as a positive reference for national identity. Considering historical data and those originated from a survey carried out in three regions of the country with young people of both sexes aged 18 through 24, the article demonstrates that sexual behaviors do not correspond to the socially diffused image of Brazilian sexuality - strongly patterned by gender relations.

Removal of caries using only hand instruments: a comparison of mechanical and chemo-mechanical methods

Abstract: The aim of this study was to evaluate the efficacy, comfort and efficiency of removing dentin caries using only hand instruments. The Carisolv system for caries removal consisting of a solvent gel and a set of specially designed hand instruments (chemo-mechanical) was compared to the use of conventional spoon excavators (mechanical). This was a clinical randomised controlled trial where the two techniques were compared in the same individual. The outcome variables were: complete caries removal; pain during caries removal; anaesthesia requested by the patient during caries removal; time taken to remove caries. Sixty-six individuals, each with a pair of similar cavities in permanent teeth were selected. After caries removal, a 'blinded' evaluator assessed the clinical status of the cavity, with the use of a probe. The times for caries removal of the chemo-mechanical and mechanical methods were respectively: 9.2+/-3.8 and 8.6+/-3.8 min (p>0.05). There were 4 cavities arguably presenting signs of caries after cavity preparation in the 66 cavities treated with the mechanical method and 7 in the 66 chemo-mechanical cavities (p>0,05). Some pain/discomfort was reported by 21 (32%) participants when the chemo-mechanical method was used, compared with 43 (65%) when the mechanical method was used (p 0.05). The chemo-mechanical method appeared to be more comfortable for most patients.

Observation of s-channel production of single top quarks at the Tevatron

Abstract: We report the first observation of single-top-quark production in the s channel through the combination of the CDF and D0 measurements of the cross section in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV. The data correspond to total integrated luminosities of up to 9.7 fb-1 per experiment. The measured cross section is $\sigma_s = 1.29^{+0.26}_{-0.24}$ pb. The probability of observing a statistical fluctuation of the background to a cross section of the observed size or larger is $1.8 \times 10^{-10}$, corresponding to a significance of 6.3 standard deviations for the presence of an s-channel contribution to the production of single-top quarks.