Lepton masses in a supersymmetric 3-3-1 model

We consider the mass generation for both charginos and neutralinos in a 3-3-1 supersymmetric model. We show that R-parity breaking interactions leave the electron and one of the neutrinos massless at the tree level. However, the same interactions induce masses for these particles at the 1-loop level. Unlike the similar situation in the minimal supersymmetric standard model, the masses of the neutralinos are related to the masses of the charginos.

Stop-lepton associated production at hadron colliders

At hadron colliders, the search for R-parity violating supersymmetry can probe scalar masses beyond what is covered by pair production processes. We evaluate the next-to-leading order SUSY-QCD corrections to the associated stop or sbottom production with a lepton through R-parity violating interactions. We show that higher order corrections render the theoretical predictions more stable with respect to variations of the renormalization and factorization scales and that the total cross section is enhanced by a factor up to 70% at the Tevatron and 50% at the LHC. We investigate in detail how the heavy supersymmetric states decouple from the next-to-leading order process, which gives rise to a theory with an additional scalar leptoquark. In this scenario the inclusion of higher order QCD corrections increases the Tevatron reach on leptoquark masses by up to 40 GeV and the LHC reach by up to 200 GeV. (C) 2003 Published by Elsevier B.V. B.V.

Can the meson cloud explain the nucleon strangeness?

We use a version of the meson cloud model, including the kaon and the K-* contributions, to estimate the electric and magnetic strange form factors of the nucleon. We compare our results with the recent measurements of the strange quark contribution to parity-violating asymmetries in the forward G0 electron-proton scattering experiment. We conclude that it is very important to determine experimentally the electric and magnetic strange form factors, and not only the combination G(E)(s)+eta G(M)(s), if one does really intend to understand the strangeness of the nucleon.

Search for supersymmetry in pp collisions at 7 TeV in events with jets and missing transverse energy

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Magnetic flux inversion in charged BPS vortices in a Lorentz-violating Maxwell-Higgs framework

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for scalar leptoquarks and T-odd quarks in the acoplanar jet topology using 2.5 fb(-1) of p(p)over-bar collision data at root s=1.96 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for three-jet resonances in pp collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Cornering the unphysical vertex

In the classical pure spinor worldsheet theory of AdS(5) x S-5 there are some vertex operators which do not correspond to any physical excitations. We study their flat space limit. We find that the BRST operator of the worldsheet theory in flat space-time can be nontrivially deformed without deforming the worldsheet action. Some of these deformations describe the linear dilaton background. But the deformation corresponding to the nonphysical vertex differs from the linear dilaton in not being worldsheet parity even. The nonphysically deformed worldsheet theory has nonzero beta-function at one loop. This means that the classical Type IIB SUGRA backgrounds are not completely characterized by requiring the BRST symmetry of the classical worldsheet theory; it is also necessary to require the vanishing of the one-loop beta-function.

Search for Sneutrino Production in e mu Final States in 5.3 fb(-1) of p(p)over-bar Collisions at root s = 1.96 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Observing Higgs dark matter at the CERN LHC

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for scalar neutrino superpartners in e+mu final states in p(p)over-bar collisions at root s=1.96 TeV

We report a search for R-parity-violating production and decay of sneutrino particles in the e mu final state with 1.04 +/- 0.06 fb(-1) of data collected with the D(0) detector at the Fermilab Tevatron Collider in 2002-2006. Good agreement between the data and the standard model prediction is observed. With no evidence for new physics, we set limits on the R-parity-violating couplings lambda'(311) and lambda(312) as a function of the sneutrino mass.

Search for Three-Jet Resonances in pp Collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Localized modes in chi((2)) media with PT-symmetric localized potential

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Search for anomalous production of multilepton events in pp collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Eficácia do tratamento Ovsynch associado à inseminação artificial prefixada em rebanhos Bos taurus e Bos indicus

O presente trabalho objetivou avaliar a eficácia do tratamento Ovsynch associado à inseminação artificial em tempo prefixado em vacas Bos taurus e Bos indicus. Foram utilizados rebanhos das raças Holandesa, Caracu, Nelore e Mantiqueira. Também foi incluído um rebanho de vacas Gir, com problemas de fertilidade. Cada rebanho foi dividido em três grupos. O grupo 1 recebeu o tratamento Ovsynch e foi inseminado em tempo prefixado. O grupo 2 foi inseminado no cio induzido com cloprostenol. O grupo 3 foi inseminado no cio natural. As taxas de concepção e de prenhez foram determinadas por ultra-sonografia. Não existiu interação significativa das variáveis reprodutivas analisadas para rebanho, idade, período pós-parto, número de parição e presença do bezerro. A taxa de concepção não diferiu (P>0,05) entre os grupos, ao passo que a taxa de prenhez foi superior (P<0,05) nos grupos 1 e 2 em comparação ao grupo 3. No rebanho Gir, o tratamento Ovsynch não alterou a taxa de concepção nem a de prenhez. Independentemente da raça, os tratamentos Ovsynch e cloprostenol não afetam a taxa de concepção, mas melhoram a taxa de prenhez. O tratamento Ovsynch não aumenta a fertilidade de vacas com problemas reprodutivos inespecíficos.