Quons as su(2) Irreducible Tensor Operators

We prove that, for the quon algebra, which interpolates between the Bose and Fermi statistics and depends on a free parameter q,it is possible to build an su(2) irreducible representation. One of the consequences of this fact is that the quons couple via the same angular momentum coupling rules obeyed by ordinary bosons and fermions.Comment: 8 pages,Late

Quons Restricted to the Antisymmetric Subspace: Formalism and Applications

In this work we develop a formalism to treat quons restricted to the antisymmetric part of their many-body space. A model in which a system of identical quons interact through a pairing force is then solved within this restriction and the differences between our solution and the usual fermionic model solution are then presented and discussed in detail. Possible connections to physical systems are also considered.Comment: 12 pages, 3 figure

Aspectos técnico-ambientais da produção orgânica na região citrícola do Vale do Rio Caí, RS.

Há uma preocupação crescente sobre a necessidade de produção e consumo de alimentos mais saudáveis, sem uso de agrotóxicos nem fertilizantes sintético-industriais. Neste contexto se insere a prática da agricultura orgânica, que, contudo, apresenta resultados ainda pouco avaliados nos meios acadêmicos e científicos. Assim, pretendeu-se nesta pesquisa diagnosticar aspectos técnico-ambientais da produção orgânica na região citrícola do Vale do Rio Caí, no Rio Grande do Sul. Inicialmente, foram selecionadas propriedades de oito agricultores familiares, todas já convertidas ao sistema orgânico de produção, sendo aplicadas entrevistas semi-estruturadas. Os produtores mostram-se satisfeitos com o sistema orgânico de produção e revelam bom conhecimento sobre o ambiente, plantas, solos e processos agroecológicos, adquiridos através da participação em eventos técnicos e em reuniões da Cooperativa Ecocitrus. A constante troca de experiências entre esses agricultores tem melhorado sua qualificação técnica, além de melhor conscientizá-los nos aspectos políticos, econômicos e sociais

Measurement of the Bottom contribution to non-photonic electron production in p+pp+p collisions at s\sqrt{s} =200 GeV

The contribution of $B$ meson decays to non-photonic electrons, which are mainly produced by the semi-leptonic decays of heavy flavor mesons, in $p+p$ collisions at $\sqrt{s} =$ 200 GeV has been measured using azimuthal correlations between non-photonic electrons and hadrons. The extracted $B$ decay contribution is approximately 50% at a transverse momentum of $p_{T} \geq 5$ GeV/$c$. These measurements constrain the nuclear modification factor for electrons from $B$ and $D$ meson decays. The result indicates that $B$ meson production in heavy ion collisions is also suppressed at high $p_{T}$.Comment: 6 pages, 4 figures, accepted by PR

BB flavour tagging using charm decays at the LHCb experiment

An algorithm is described for tagging the flavour content at production of neutral $B$ mesons in the LHCb experiment. The algorithm exploits the correlation of the flavour of a $B$ meson with the charge of a reconstructed secondary charm hadron from the decay of the other $b$ hadron produced in the proton-proton collision. Charm hadron candidates are identified in a number of fully or partially reconstructed Cabibbo-favoured decay modes. The algorithm is calibrated on the self-tagged decay modes $B^+ \to J/\psi \, K^+$ and $B^0 \to J/\psi \, K^{*0}$ using $3.0\mathrm{\,fb}^{-1}$ of data collected by the LHCb experiment at $pp$ centre-of-mass energies of $7\mathrm{\,TeV}$ and $8\mathrm{\,TeV}$. Its tagging power on these samples of $B \to J/\psi \, X$ decays is $(0.30 \pm 0.01 \pm 0.01) \%$.Comment: All figures and tables, along with any supplementary material and additional information, are available at http://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-027.htm

Evidence for the strangeness-changing weak decay Ξb−→Λb0π−\Xi_b^-\to\Lambda_b^0\pi^-

Using a $pp$ collision data sample corresponding to an integrated luminosity of 3.0~fb$^{-1}$, collected by the LHCb detector, we present the first search for the strangeness-changing weak decay $\Xi_b^-\to\Lambda_b^0\pi^-$. No $b$ hadron decay of this type has been seen before. A signal for this decay, corresponding to a significance of 3.2 standard deviations, is reported. The relative rate is measured to be ${{f_{\Xi_b^-}}\over{f_{\Lambda_b^0}}}{\cal{B}}(\Xi_b^-\to\Lambda_b^0\pi^-) = (5.7\pm1.8^{+0.8}_{-0.9})\times10^{-4}$, where $f_{\Xi_b^-}$ and $f_{\Lambda_b^0}$ are the $b\to\Xi_b^-$ and $b\to\Lambda_b^0$ fragmentation fractions, and ${\cal{B}}(\Xi_b^-\to\Lambda_b^0\pi^-)$ is the branching fraction. Assuming $f_{\Xi_b^-}/f_{\Lambda_b^0}$ is bounded between 0.1 and 0.3, the branching fraction ${\cal{B}}(\Xi_b^-\to\Lambda_b^0\pi^-)$ would lie in the range from $(0.57\pm0.21)\%$ to $(0.19\pm0.07)\%$.Comment: 7 pages, 2 figures, All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-047.htm

A systematic review of the effects of exercise interventions on body composition in HIV+ adults

Over the years, physical activity and exercise have been used to positively impact the health and quality of life of persons infected with HIV and, more recently, has been associated with a spectrum of body composition changes. The aim of this review was to examine the effects of various exercise interventions on body composition in HIV positive adults, using a search strategy of randomized, controlled trials (RCTs). A systematic review was performed by five independent reviewers using a predetermined protocol adapted from previous research for assessing the articles for inclusion, the extracted data, and methodological quality. Eight RCTs involving 430 (26% female) HIV positive adults performing exercise a minimum of thrice weekly for at least six weeks were finally selected: Four were progressive resistance training (PRT) studies, three were aerobic training (AT) studies, and one involved yoga. In the PRT studies, there were significant increases in three anthropometric measures, namely, body mass, sum of skinfolds and sum of limb girths. In the AT studies, significant decreases were found in seven anthropometric measures, namely, body mass index, waist-hip ratio, body mass, triceps skinfold, waist circumference and sum of skinfolds. With yoga, the changes were nonsignificant. Exercise contributes to improved body composition and, when applied safely, appears to be beneficial for adults living with HIV/AIDS. However, these findings should be interpreted cautiously due to the relatively few RCTs published to date. Future studies would benefit from increased attention to sample size, female participants, participant follow-up, complete statistical analysis and intention-to-treat analysis.Scopu

Impacts of climate changes on risk zoning for cowpea in the Amazonian tropical conditions

The climate risk zoning was carried out for cowpea cultivated in northeastern Amazonia, Pará state, Brazil. Système d’Analyse Régionale des Risques Agroclimatologiques (SARRA) crop model was used and calibrated from data obtained in field experiments conducted between 2013 and 2016 in Castanhal, state of Pará. Low climate risk areas were defined as those with water requirement satisfaction index (WRSI) greater than or equal to 0.5 during flowering and early grain development and less than 20 mm of total rainfall during grain maturation and harvest for at least 80% of the simulated sowings of the crop. Simulations of the current and future climate conditions were carried out with the regional climate modelling system version 4 (RegCM4) nested with the HadGEM2 global circulation model with RCP 4.5 IPCC-AR4 scenario. The results show that climate changes are likely to reduce the duration of the optimal period for sowing cowpea in the mentioned regioninfo:eu-repo/semantics/publishedVersio

Longitudinal double-spin asymmetry and cross section for inclusive neutral pion production at midrapidity in polarized proton collisions at sqrt(s) = 200 GeV

We report a measurement of the longitudinal double-spin asymmetry A_LL and the differential cross section for inclusive Pi0 production at midrapidity in polarized proton collisions at sqrt(s) = 200 GeV. The cross section was measured over a transverse momentum range of 1 < p_T < 17 GeV/c and found to be in good agreement with a next-to-leading order perturbative QCD calculation. The longitudinal double-spin asymmetry was measured in the range of 3.7 < p_T < 11 GeV/c and excludes a maximal positive gluon polarization in the proton. The mean transverse momentum fraction of Pi0's in their parent jets was found to be around 0.7 for electromagnetically triggered events.Comment: 6 pages, 3 figures, submitted to Phys. Rev. D (RC