Illuminating the charged leptons in the proton

The description of the structure of proton is fundamental in order to describe the standard model processes at the LHC as well as for the searching of New Physics. Quantum fluctuations imply the presence of photons and leptons inside the proton, which admit a parton distribution function (PDF). Although the lepton PDFs are expected to be small, its presence opens new production mechanisms. In order to explore the lepton - induced processes at the LHC, a precise determination of the leptonic content of the proton is needed. In this paper we propose to constrain the content of charged leptons inside the proton through the study of the QED Compton scattering in ultraperipheral proton - nucleus collisions at the LHC. We estimate the total cross sections and associated distributions considering different models for the lepton PDFs and distinct lepton flavours. We demonstrate that a future experimental analysis of this process is feasible and that it can be used to constrain the content of electrons, muons and taus inside the proton.Comment: 10 pages, 3 figures, 1 table. Improved version to be published in PR

An Improved Algorithm for Generating Database Transactions from Relational Algebra Specifications

Alloy is a lightweight modeling formalism based on relational algebra. In prior work with Fisler, Giannakopoulos, Krishnamurthi, and Yoo, we have presented a tool, Alchemy, that compiles Alloy specifications into implementations that execute against persistent databases. The foundation of Alchemy is an algorithm for rewriting relational algebra formulas into code for database transactions. In this paper we report on recent progress in improving the robustness and efficiency of this transformation

Alguns aspectos da geoestratégia global do lítio : o caso de Portugal

O lítio é um metal com uma multiplicidade de aplicações numa grande diversidade de indústrias. Utiliza-se na forma metálica, de diversos compostos químicos ou de concentrado mineral, em sectores como as indústrias vidreira, cerâmica, farmacêutica, electrónica, agro-química, baterias, entre outras. O crescente consumo a nível global tem sido dominado pelas indústrias cerâmica e vidreira. Contudo, o desenvolvimento tecnológico dos veículos eléctricos, a implementação no mercado e as previsões de crescimento global deste sector, fazem prever um significativo crescimento na procura de lítio, já que é a base das baterias utilizadas nestes veículos. Deste modo, os projectos mineiros de lítio proliferam por todo o globo, sobretudo em depósitos do tipo salmoura e pegmatitos. Em Portugal, os recursos de Li são do tipo pegmatito e têm sido explorados conjuntamente com os feldspatos, para utilização na indústria cerâmica. Devido ao potencial existente em Portugal neste tipo de recursos, é necessária a aplicação de uma nova metodologia que contribua para a maximização do valor do recurso pegmatito e para avaliar a viabilidade de produção de carbonato de Li

Moyens du bord: espaces en suspension, temps interstitiels et activités socioculturelles en prison

A dinamização do sector sociocultural é atualmente uma parte integrante da gestão das prisões portuguesas. Neste contexto, reclusos são incentivados a participar ativamente, fazendo uso das suas competências sociais e artísticas, e beneficiando de alívios na pressão disciplinar da prisão. Frequentadores destes “espaços suspensos” onde se organizam atividades lúdicas e artísticas, alguns reclusos tornam-se “prata da casa”, simultaneamente imagem pública da prisão e beneficiários de uma relação próxima com os técnicos. Propomos aqui a análise desta posição ambígua e das formas como a “prata da casa” nos permitem pensar sobre esta modalidade penal em que os reclusos assumem uma parte da administração da sua própria pena.The sociocultural sector has been in recent times an integral part of Portuguese prison management. Inmates are encouraged to proactively engage in these activities, to put their social and artistic skills to use, and to find in them some relief in the prison’s disciplinary pressure. As they participate in these “suspended spaces” wherein ludic and artistic activities are organized, certain inmates become “prata da casa” (homegrown pride), acting as the prison’s public image and benefiting from a close relationship with the prison staff. Drawing from this ambiguous status, we propose an analysis of a penal modality whereby inmates partly take charge of managing their own sentence.Moyens du bord: Espaces en suspension, temps interstitiels et activités socioculturelles en prison La dynamisation du secteur socioculturel fait actuellement partie intégrante de la gestion des prisons portugaises. Dans ce contexte, les détenus sont encouragés à y participer activement, en employant leurs compétences sociales et artistiques et en bénéficiant de soulagements par rapport à la pression disciplinaire de la prison. Dans ces « espaces en suspension », où des activités ludiques et artistiques sont organisées, certains des détenus deviennent « prata da casa » (moyens du bord), en agissant, en même temps, comme l’image publique de la prison et en bénéficiant d’une relation plus étroite avec le personnel. Cet article vise à analyser cette ambiguïté et la manière dont les « moyens du bord » nous permettent de réfléchir sur cette modalité pénale où les détenus prennent à leur compte une partie de l’administration de leurs propres peines.info:eu-repo/semantics/publishedVersio

Exclusive dilepton production at forward rapidities in PbPbPbPb collisions

The dilepton production in diffractive and exclusive processes at forward rapidities considering ultraperipheral $PbPb$ collisions at the LHC is investigated. Predictions for the $e^+ e^-$, $\mu^+ \mu^-$ and $\tau^+ \tau^-$ cross sections are presented taking into account of realistic cuts that can be implemented by the LHCb Collaboration in a future experimental analysis. Our results indicate that the background associated with the diffractive production can be strongly suppressed and the exclusive processes can be cleanly separated. For the $\tau^+ \tau^-$ production, the semi and purely leptonic decay channels are considered. Our results indicate that a future experimental analysis of the dilepton production at the LHCb is feasible and can be useful to search for BSM physics.Comment: 7 pages, 3 figures, 3 table

Coherent and incoherent J/ΨJ/\Psi photoproduction in PbPbPbPb collisions at the LHC, HE -- LHC and FCC

The coherent and incoherent $J/\Psi$ photoproduction in $PbPb$ collisions are investigated considering the possible states of nucleon configurations in the nuclear wave function and taking into account of the non - linear corrections to the QCD dynamics. The cross sections and the rapidity and transverse momentum distributions are estimated for the energies of the next run of the LHC, High -- Energy LHC and Future Circular Collider. Our results indicate that a future experimental analysis of these processes will be useful to discriminate between different approaches for the QCD dynamics as well to improve our description of the gluon saturation effects.Comment: 7 pages, 3 figures, 1 tabl

Foramen of Winslow hernia: case report of a minimally invasive approach

Foramen of Winslow hernias account for 8% of all internal hernias. Their non-specific presentation and often late diagnosis are associated with an estimated mortality of 50%. The use of complementary diagnostic methods facilitates the diagnosis and planning of the therapeutic strategy. Urgent surgery is the appropriate treatment due to the risk of intestinal ischemia, being laparotomy the main form of approach described. Few cases of laparoscopy are referred to in the literature.info:eu-repo/semantics/publishedVersio

accuracy and precision of statistical descriptors obtained from multidimensional diffusion signal inversion algorithms

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Searches for axion-like particles via γγ\gamma \gamma fusion at future e+e−\mathrm{e}^+\mathrm{e}^- colliders

Opportunities for searches for axion-like particles (ALPs) coupling to photons in $\mathrm{e}^+\mathrm{e}^-$ collisions at the Future Circular Collider (FCC-ee) and International Linear Collider (ILC) are investigated. We perform a study of the photon-fusion production of ALPs decaying into two photons, $\mathrm{e}^+\mathrm{e}^- \overset{\gamma \gamma}{\longrightarrow} \mathrm{e}^{+}\;a(\gamma \gamma)\;\mathrm{e}^{-}$, over the light-by-light continuum background, for the planned FCC-ee and ILC center-of-mass energies and integrated luminosities. An analysis of the feasibility measurements is presented using parametrized simulations for two types of detectors. Upper limits at 95% confidence level (CL) on the cross section for ALP production, $\sigma(\gamma \gamma \to a \to \gamma \gamma)$, and on the ALP-photon coupling are obtained over the $m_a \approx 0.1$--1000 GeV ALP mass range, and compared to current and future collider searches. Production cross sections down to $\sigma(\gamma \gamma \to a \to \gamma \gamma) \approx 1$ fb (1 ab) will be probed at $m_a\approx 1$ (300) GeV, corresponding to constraints on the axion-photon coupling as low as $g_\mathrm{a\gamma \gamma} \approx 2\cdot10^{-3}$ TeV$^{-1}$