Lepton Number Violating Radiative WW Decay in Models with R-parity Violation

Models with explicit R-parity violation can induce new rare radiative decay modes of the $W$ boson into single supersymmetric particles which also violate lepton number. We examine the rate and signature for one such decay, $W\rightarrow \tilde l\gamma$, and find that such a mode will be very difficult to observe, due its small branching fraction, even if the lepton number violating coupling in the superpotential is comparable in strength to electromagnetism. This parallels a similar result obtained earlier by Hewett in the case of radiative $Z$ decays.Comment: 10 pages, 2 figures(available on request), LaTex, ANL-HEP-PR-92-8

Multi-Higgs doublet models: the Higgs-fermion couplings and their sum rules

This is the second of a series of papers that explores the physical parameterization, sum rules and unitarity bounds arising from a non-minimal scalar sector of the Standard Model (SM) that consists of N Higgs doublets. In this paper, we focus on the structure and implication of the Yukawa interactions that couple the N scalar doublets to the SM fermions. We employ the charged Higgs basis, which is defined as the basis of scalar fields such that the neutral scalar field vacuum expectation value resides entirely in one of the N scalar doublet fields, and the charged components of the remaining N-1 scalar doublet fields are the physical (mass-eigenstate) charged Higgs fields. Based on the structure of the Yukawa Lagrangian of the model (and as a consequence of tree-level unitarity), one may deduce numerous sum rules, several of which have not appeared previously in the literature. These sum rules can be used to uncover intimate relations between the structure of the Higgs-fermion couplings and the scalar/gauge couplings. In particular, we show that the approximate alignment limit, in which the W+W- and ZZ couplings to the observed Higgs boson are approximately SM-like, imposes significant constraints on the Higgs-fermion couplings.Comment: 24 pages, 2 figures, 4 tables, uses jheppub.sty. Two typographical errors corrected, one clarification added and one reference updated in v

A INDÚSTRIA DOS JOGOS ELETRÔNICOS: NOVAS TECNOLOGIAS, PROPRIEDADE INTELECTUAL E CENÁRIO MUNDIAL E BRASILEIRO

O presente artigo tem como objetivo identificar características da indústria de jogos eletrônicos, tendo em vista o crescimento considerável do valor do mercado mundial de jogos eletrônicos nos últimos anos.  A evolução da tecnologia tem permitido o surgimento de novos setores como o setor de jogos. Este setor tem possibilitado a disponibilização de entretenimento, principalmente com o advento da internet e da plataforma online. Assim, analisa-se como o surgimento de novas tecnologias possibilitaram novos modelos de negócio e o desenvolvimento do setor de jogos eletrônicos. Verifica-se como a transformação na economia global interfere na gestão de propriedade intelectual.Examina-se a importância da propriedade intelectual no setor de jogos eletrônicos, tendo em vista que os jogos possuem dois elementos essenciais: o programa de computador, além de elementos individuais (ou seja, os personagens, sua trilha sonora, configurações, etc.), que podem ser protegidos por direitos autorais.Nesta seara, verifica-se que não existe uma classificação explícita para jogos eletrônicos nos termos da legislação brasileira, assim há a opção por um regime no qual é possível a proteção nestas duas esferas (direito autoral e programa de computador). Neste sentido, os elementos audiovisuais dos jogos eletrônicos podem ser enquadrados na definição da Lei de Direito Autoral de obra audiovisual (art. 5º, VIII, “i” da Lei 9.610/1996) e o programa de computador seria protegido pela Lei nº 9.279, de 14 de maio de 1996.Ademais, identificam-se o cenário mundial e brasileiro da indústria de jogos eletrônicos, tendo em vista o crescimento considerável do valor do mercado mundial de jogos eletrônicos nos últimos anos

Caracterização dos agroecossistemas e manejo de germoplasma de Citrullus em três regiões do Nordeste brasileiro.

Sendo assim, este trabalho teve como objetivos caracterizar, estudar e descrever os agroecossistemas nordestinos representados pelos distritos de Jamarí-MA, Massaroca-BA e Urimamã-PE

Non-Abelian Discrete Symmetries and Neutrino Masses: Two Examples

Two recent examples of non-Abelian discrete symmetries (S_3 and A_4) in understanding neutrino masses and mixing are discussed.Comment: 16 pages, no figure, invited contribution to NJP focus issue on neutrino

Leptonic CP Violation in Supersymmetric Standard Model

We point out the possibility of spontaneous and hard CP-violation in the scalar potential of R-parity broken supersymmetric Standard Model. The existence of spontaneous CP-violation depends crucially on the R-parity breaking terms in the superpotential and, in addition, on the choice of the soft supersymmetry breaking terms. Unlike in theories with R-parity conservation, it is natural, in the context of the present model, for the sneutrinos to acquire (complex) vacuum expectation values. In the context of this model we examine here the global implications, like the strength of the CP-violating interactions and the neutrino masses.Comment: REVTEX, 15 page

The dilaton-dominated supersymmetry breaking scenario in the context of the non-minimal supersymmetric model

The phenomenological consequences of the dilaton-type soft supersymmetry breaking terms in the context of the next to minimal supersymmetric standard model are investigated. We always find a very low top quark mass. As a consequence such string vacua are excluded by recent experimental results. The viability of the solution of the $\mu$ term through the introduction of a gauge singlet field is also briefly discussed.Comment: 10 pages,LATE

Low-Energy Thermal Leptogenesis in an Extended NMSSM Model

Thermal leptogenesis in the canonical seesaw model in supersymmetry suffers from the incompatibility of a generic lower bound on the mass scale of the lightest right-handed neutrino and the upper bound on the reheating temperature of the Universe after inflation. This is resolved by adding an extra singlet superfield, with a discrete $Z_2$ symmetry, to the NMSSM (Next to Minimal Supersymmetric Standard Model). This generic mechanism is applicable to any supersymmetric model for lowering the scale of leptogenesis.Comment: 16 pages, revtex, 9 eps figure

Bilinear R-parity violation with flavor symmetry

Bilinear R-parity violation (BRPV) provides the simplest intrinsically supersymmetric neutrino mass generation scheme. While neutrino mixing parameters can be probed in high energy accelerators, they are unfortunately not predicted by the theory. Here we propose a model based on the discrete flavor symmetry $A_4$ with a single R-parity violating parameter, leading to (i) correct Cabbibo mixing given by the Gatto-Sartori-Tonin formula, and a successful unification-like b-tau mass relation, and (ii) a correlation between the lepton mixing angles $\theta_{13}$ and $\theta_{23}$ in agreement with recent neutrino oscillation data, as well as a (nearly) massless neutrino, leading to absence of neutrinoless double beta decay.Comment: 16 pages, 3 figures. Extended version, as published in JHE

Broken R-parity, stop decays, and neutrino physics

We discuss the phenomenology of the lightest stop in models where R-parity is broken by bilinear superpotential terms. In this class of models we consider scenarios where the R-parity breaking two-body decay ~t_1->\tau^+b competes with the leading three-body decays such as ~t_1->W^+b~\chi^0_1. We demonstrate that the R-parity violating decay can be sizable and in some parts of the parameter space even the dominant one. Moreover we discuss the expectations for \~t_1->\mu^+b and ~t_1->e^+b. The recent results from solar and atmospheric neutrinos suggest that these are as important as the tau bottom mode. The \~t_1->l^+b decays are of particular interest for hadron colliders, as they may allow a full mass reconstruction of the lighter stop. Moreover these decay modes allow cross checks on the neutrino mixing angle involved in the solar neutrino puzzle complementary to those possible using neutralino decays. For the so--called small mixing angle or SMA solution ~t_1->e^+b should be negligible, while for the large mixing angle type solutions all ~t_1->l^+b decays should have comparable magnitude.Comment: 51 pages, 6 figures, LaTeX2e and RevTeX4, published versio