R Parity violating enhancement of Bu -> l nu and Bc -> l nu

We study the decays Bu -> l nu and Bc -> l nu in the context of the Minimal Supersymmetric Standard Model (MSSM) with explicit R parity violation. We analyse the correlation between the two decays and show that branching ratios (BRs) for Bc -> l nu may be of order 5% (over 40% in one case), without violating current bounds on Bu -> l nu. Although Bc mesons are inaccessible at the e+e- B factories, such large BRs for Bc -> l nu would possibly be within experimental observability at LEP and the Tevatron Run II, with much larger yields expected at the hadronic B factories. We also update some earlier bounds on products of R parity violating couplings in the light of new experimental results.Comment: Notation in the introduction clarified, version to be published in PLB. (12 pages, 2 figures

Non-minimal neutral Higgs bosons at LEP2

We study the phenomenology of the neutral Higgs sector of a non-SUSY non-minimal Standard Model. Models with more than one Higgs doublet are possible, and may contain neutral Higgs scalars with branching ratios significantly different to those of the Minimal Standard Model Higgs boson. We show how these differences may be exploited at LEP2 in order to distinguish the non-minimal Standard Model from the minimal version.Comment: 12 pages inc 4 figures, Latex, to appear in Physics Letters

Searching for a light Fermiophobic Higgs Boson at the Tevatron

We propose new production mechanisms for light fermiophobic Higgs bosons ($h_f$) with suppressed couplings to vector bosons ($V$) at the Fermilab Tevatron. These mechanisms (e.g. $qq'\to H^\pm h_f$) are complementary to the conventional process $qq'\to Vh_f$, which suffers from a strong suppression of $1/\tan^2\beta$ in realistic models with a $h_f$. The new mechanisms extend the coverage at the Tevatron Run II to the larger $\tan\beta$ region, and offer the possibility of observing new event topologies with up to 4 photons.Comment: 15 pages, including 5 eps-figure

Evolução do processo de capacitação dos servidores da Universidade Federal Do Maranhão (UFMA) / Evolution of the training process of the Federal University Of Maranhão (UFMA)

Capacitar funcionários, de quaisquer iniciativas é dever de toda boa empresa que almeja um desempenho eficiente de sua equipe.  No âmbito federal, a capacitação é tratada já na Lei 8.112/1990, artigo 87. Na UFMA esta atividade vem sendo desenvolvida desde então, mas ganhou mais relevância a partir do início do século XX, em especial, em 2012, depois da Implementação do Sistema Integrado de Gestão (SIG), por meio da ferramenta Sistema de Recursos Humanos (SIGRH), que permitiu, além da informatização dos dados dos funcionários, uma maior divulgação dos cursos, facilitando, inclusive, a inscrição dos servidores. O objetivo deste trabalho, centrado nesta questão, é mostrar a evolução desse trabalho de capacitação, em especial, a partir da segunda metade de 2019, quando foi implementada a capacitação por meio da plataforma Moodle, disponibilizada pela Diretoria Interdisciplinar de Tecnologias na Educação (DINTE), tomando como base para análise, cursos de habilidades linguísticas. O trabalho adota abordagens descritivo-analítica e o aparato teórico que o norteia está centrado, sobretudo, na legislação vigente e nas Portarias veiculadas pela Universidade Federal do Maranhão.

J/ψJ/\psi suppression in Pb+Pb collisions and pTp_T broadening

We have analysed the NA50 data, on the centrality dependence of $p_T$ broadening of $J/\psi$'s, in Pb+Pb collisions, at the CERN-SPS. The data were analysed in a QCD based model, where $J/\psi$'s are suppressed in 'nuclear' medium. Without any free parameter, the model could explain the NA50 $p_T$ broadening data. The data were also analysed in a QGP based threshold model, where $J/\psi$ suppression is 100% above a critical density. The QGP based model could not explain the NA50 $p_T$ broadening data. We have also predicted the centrality dependence of $J/\psi$ suppression and $p_T$ broadening at RHIC energy. Both the models, the QGP based threshold model and the QCD based nuclear absorption model, predict $p_T$ broadening very close to each other.Comment: The paper was completely revised. The conclusion is also changed. 5 pages, 4 figure

The seesaw mechanism at TeV scale in the 3-3-1 model with right-handed neutrinos

We implement the seesaw mechanism in the 3-3-1 model with right-handed neutrinos. This is accomplished by the introduction of a scalar sextet into the model and the spontaneous violation of the lepton number. We identify the Majoron as a singlet under $SU_L(2)\otimes U_Y(1)$ symmetry, which makes it safe under the current bounds imposed by electroweak data. The main result of this work is that the seesaw mechanism works already at TeV scale with the outcome that the right-handed neutrino masses lie in the electroweak scale, in the range from MeV to tens of GeV. This window provides a great opportunity to test their appearance at current detectors, though when we contrast our results with some previous analysis concerning detection sensitivity at LHC, we conclude that further work is needed in order to validate this search.Comment: about 13 pages, no figure

Solar Neutrino Masses and Mixing from Bilinear R-Parity Broken Supersymmetry: Analytical versus Numerical Results

We give an analytical calculation of solar neutrino masses and mixing at one-loop order within bilinear R-parity breaking supersymmetry, and compare our results to the exact numerical calculation. Our method is based on a systematic perturbative expansion of R-parity violating vertices to leading order. We find in general quite good agreement between approximate and full numerical calculation, but the approximate expressions are much simpler to implement. Our formalism works especially well for the case of the large mixing angle MSW solution (LMA-MSW), now strongly favoured by the recent KamLAND reactor neutrino data.Comment: 34 pages, 14 ps figs, some clarifying comments adde

Reconstructing Neutrino Properties from Collider Experiments in a Higgs Triplet Neutrino Mass Model

We extend the minimal supersymmetric standard model with bilinear R-parity violation to include a pair of Higgs triplet superfields. The neutral components of the Higgs triplets develop small vacuum expectation values (VEVs) quadratic in the bilinear R-parity breaking parameters. In this scheme the atmospheric neutrino mass scale arises from bilinear R-parity breaking while for reasonable values of parameters the solar neutrino mass scale is generated from the small Higgs triplet VEVs. We calculate neutrino masses and mixing angles in this model and show how the model can be tested at future colliders. The branching ratios of the doubly charged triplet decays are related to the solar neutrino angle via a simple formula.Comment: 19 pages, 4 figures; one formula corrected, two author's names corrected; some explanatory comments adde

Exploring flavor structure of supersymmetry breaking from rare B decays and unitarity triangle

We study effects of supersymmetric particles in various rare B decay processes as well as in the unitarity triangle analysis. We consider three different supersymmetric models, the minimal supergravity, SU(5) SUSY GUT with right-handed neutrinos, and the minimal supersymmetric standard model with U(2) flavor symmetry. In the SU(5) SUSY GUT with right-handed neutrinos, we consider two cases of the mass matrix of the right-handed neutrinos. We calculate direct and mixing-induced CP asymmetries in the b to s gamma decay and CP asymmetry in B_d to phi K_S as well as the B_s--anti-B_s mixing amplitude for the unitarity triangle analysis in these models. We show that large deviations are possible for the SU(5) SUSY GUT and the U(2) model. The pattern and correlations of deviations from the standard model will be useful to discriminate the different SUSY models in future B experiments.Comment: revtex4, 36 pages, 10 figure

Three-body decays of Higgs bosons at LEP2 and application to a hidden fermiophobic Higgs

We study the decays of Higgs bosons to a lighter Higgs boson and a virtual gauge boson in the context of the non-supersymmetric Two-Higgs-Doublet-Model (2HDM). We consider the phenomenological impact at LEP2 and find that such decays, when open, may be dominant in regions of parameter space and thus affect current Higgs boson search techniques. Three-body decays would be a way of producing light neutral Higgs bosons which have so far escaped detection at LEP due to suppressed couplings to the $Z$, and are of particular importance in the 2HDM (Model I) which allows both a light fermiophobic Higgs and a light charged scalar.Comment: 23 pages Latex, 9 figures, references added, alterations to text in sections 3 and 5, some graphs changed slightly, to appear in Nuclear Physics