3,149 research outputs found

    Efeito da altitude sobre o crescimento e desenvolvimento de quatro genótipos de mamona.

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    Torsion Phenomenology at the LHC

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    We explore the potential of the CERN Large Hadron Collider (LHC) to test the dynamical torsion parameters. The form of the torsion action can be established from the requirements of consistency of effective quantum field theory. The most phenomenologically relevant part of the torsion tensor is dual to a massive axial vector field. This axial vector has geometric nature, that means it does not belong to any representation of the gauge group of the SM extension or GUT theory. At the same time, torsion should interact with all fermions, that opens the way for the phenomenological applications. We demonstrate that LHC collider can establish unique constraints on the interactions between fermions and torsion field considerably exceeding present experimental lower bounds on the torsion couplings and its mass. It is also shown how possible non-universal nature of torsion couplings due to the renormalization group running between the Planck and TeV energy scales can be tested via the combined analysis of Drell-Yan and ttˉt\bar{t} production processes

    Dirac and Majorana heavy neutrinos at LEP II

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    The possibility of detecting single heavy Dirac and Majorana neutrinos at LEP II is investigated for heavy neutrino masses in the range MN=(s/2,s)M_N=(\sqrt s/2, \sqrt s). We study the process e+eνqiqˉje^+e^- \longrightarrow \nu_{\ell} \ell q_i \bar q_j as a clear signature for heavy neutrinos. Numerical estimates for cross sections and distributions for the signal and the background are calculated and a Monte Carlo reconstruction of final state particles after hadronization is presented.Comment: 4 pages, 8 figure

    Potencial agrícola de bactérias endofíticas obtidas de bambu Guadua spp.

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    Esta pesquisa teve por objetivo caracterizar as bactérias endofíticas de Guadua spp. e estimar o seu potencial de uso agrícola como solubilizados de fosfato e fixação de nitrogênio.bitstream/item/209190/1/26952.pdfVersão impressa publicada em 2020

    Discriminating among the theoretical origins of new heavy Majorana neutrinos at the CERN LHC

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    A study on the possibility of distinguishing new heavy Majorana neutrino models at LHC energies is presented. The experimental confirmation of standard neutrinos with non-zero mass and the theoretical possibility of lepton number violation find a natural explanation when new heavy Majorana neutrinos exist. These new neutrinos appear in models with new right-handed singlets, in new doublets of some grand unified theories and left-right symmetrical models. It is expected that signals of new particles can be found at the CERN high-energy hadron collider (LHC). We present signatures and distributions that can indicate the theoretical origin of these new particles. The single and pair production of heavy Majorana neutrinos are calculated and the model dependence is discussed. Same-sign dileptons in the final state provide a clear signal for the Majorana nature of heavy neutrinos, since there is lepton number violation. Mass bounds on heavy Majorana neutrinos allowing model discrimination are estimated for three different LHC luminosities.Comment: 7 pages, 5 figure
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