55 research outputs found

    RNS derivation of N-point disk amplitudes from the revisited S-matrix approach

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    In the past year, in arXiv:1208.6066 we proposed a revisited S-matrix approach to efficiently find the bosonic terms of the open superstring low energy effective lagrangian (OSLEEL). This approach allows to compute the αN{\alpha'}^N terms of the OSLEEL using open superstring nn-point amplitudes in which nn is very much lower than (N+2)(N+2) (which is the order of the required amplitude to obtain those αN{\alpha'}^N terms by means of the conventional S-matrix approach). In this work we use our revisited S-matrix approach to examine the structure of the scattering amplitudes, arriving at a closed form for them. This is a RNS derivation of the formula first found by Mafra, Schlotterer and Stieberger in arXiv:1106.2645, using the Pure Spinor formalism. We have succeeded doing this for the 5, 6 and 7-point amplitudes. In order to achieve these results we have done a careful analysis of the kinematical structure of the amplitudes, finding as a by-product a purely kinematical derivation of the BCJ relations (for N=4, 5, 6 and 7). Also, following the spirit of the revisited S-matrix approach, we have found the α\alpha' expansions for these amplitudes up to α6{\alpha'}^6 order in some cases, by only using the well known open superstring 4-point amplitude, cyclic symmetry and tree level unitarity: we have not needed to compute any numerical series or any integral involving polylogarithms, at any moment.Comment: 77 pages, 3 figure

    Normal and anomalous diffusion in a bouncing ball over an irregular surface

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    The problem of a bouncing ball on a non-planar surface is investigated. We discovered that surface undulation adds a horizontal component to the impact force, which acquires a random character. Some aspects of Brownian motion are found in the horizontal distribution of the particle. On the x-axis, normal and super diffusion are observed. For the probability density's functional form, a scaling hypothesis is presented.Comment: 12 pages, 8 figures, 1 tabl

    Revisiting the S-matrix approach to the open superstring low energy effective lagrangian

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    The conventional S-matrix approach to the (tree level) open string low energy effective lagrangian assumes that, in order to obtain all its bosonic αN{\alpha'}^N order terms, it is necessary to know the open string (tree level) (N+2)(N+2)-point amplitude of massless bosons, at least expanded at that order in α\alpha'. In this work we clarify that the previous claim is indeed valid for the bosonic open string, but for the supersymmetric one the situation is much more better than that: there are constraints in the kinematical bosonic terms of the amplitude (probably due to Spacetime Supersymmetry) such that a much lower open superstring nn-point amplitude is needed to find all the αN{\alpha'}^N order terms. In this `revisited' S-matrix approach we have checked that, at least up to α4{\alpha'}^4 order, using these kinematical constraints and only the known open superstring 4-point amplitude, it is possible to determine all the bosonic terms of the low energy effective lagrangian. The sort of results that we obtain seem to agree completely with the ones achieved by the method of BPS configurations, proposed about ten years ago. By means of the KLT relations, our results can be mapped to the NS-NS sector of the low energy effective lagrangian of the type II string theories implying that there one can also find kinematical constraints in the NN-point amplitudes and that important informations can be inferred, at least up to α4{\alpha'}^4 order, by only using the (tree level) 4-point amplitude.Comment: 34 pages, 3 figure, Submitted on Aug 4, 2012, Published on Oct 15, 201

    Uso de antagonistas α-adrenérgicos n-fenilpiperazínicos, composições farmacêuticas contendo os mesmos e processos para sua preparação

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    Em 9/11/2004: Publicação do Pedido Arquivado Definitivamente - Art. 216 § 2º e Art. 17 § 2º da LPI. Publicação de pedido definitivamente arquivado devido à não apresentação de procuração ou devido à apresentação de um pedido posterior Encerrada a instância administrativa. Pode ser adquirido no Banco de Patentes do Centro de Documentação e Informação Tecnológica do INPI - CEDIN - o folheto com o relatório descritivo, reivindicações, desenhos e resumo do pedido.DepositadaSão descritos antagonistas a-adrenérgicos fenilpiperazínicos. Utilidade para o tratamento de sintomas do trato urinário inferior, incluindo o tratamento de hiperplasia benigna da próstata em mamíferos, preferencialmente humanos; são também descritas composições farmacêuticas contendo os referidos compostos e processos para sua preparação

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

    Search for single production of vector-like quarks decaying into Wb in pp collisions at s=8\sqrt{s} = 8 TeV with the ATLAS detector

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