Search for flavor changing neutral currents in top quark decays in pp collisions at 7 TeV

The results of a search for flavor changing neutral currents in top quark decays t→Zq in events with a topology compatible with the decay chain tt̄→Wb+Zq→ℓνb+ℓℓq are presented. The search is performed with a data sample corresponding to an integrated luminosity of 5.0 fb-1 of proton-proton collisions at a center-of-mass energy of 7 TeV, collected with the CMS detector at the LHC. The observed number of events agrees with the standard model prediction and no evidence for flavor changing neutral currents in top quark decays is found. A t→Zq branching fraction greater than 0.21% is excluded at the 95% confidence level. © 2012 CERN.

Higgs decay rate to two photons in a model with two fermiophobic-Higgs doublets

We consider a three Higgs doublet model with an S3 symmetry in which beside the standard model-like doublet, there are two fermiophobic doublets. Due to the new charged scalars, there is an enhancement in the two-photon decay, while the other channels have the same decay widths as the standard model neutral Higgs. The fermiophobic scalars are mass degenerated unless soft terms breaking the S3 symmetry are added. © 2013 American Physical Society.

Search in leptonic channels for heavy resonances decaying to long-lived neutral particles

A search is performed for heavy resonances decaying to two long-lived massive neutral particles, each decaying to leptons. The experimental signature is a distinctive topology consisting of a pair of oppositely charged leptons originating at a separated secondary vertex. Events were collected by the CMS detector at the LHC during pp collisions at √s = 7 TeV, and selected from data samples corresponding to 4.1 (5.1) fb-1 of integrated luminosity in the electron (muon) channel. No significant excess is observed above standard model expectations, and an upper limit is set with 95% confidence level on the production cross section times the branching fraction to leptons, as a function of the long-lived massive neutral particle lifetime. Copyright CERN.

Search for Flavor-Changing Neutral Currents in Top-Quark Decays t -> Zq in pp Collisions at root s=8 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Low mass pseudoscalar dark matter in an extended B - L model

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

Search for the Higgs boson H-2(0) at LHC in 3-3-1 model

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for neutral MSSM Higgs bosons decaying to a pair of tau leptons in pp collisions

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for long-lived neutral particles decaying to quark-antiquark pairs in proton-proton collisions at root s=8 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Light-by-light scattering with intact protons at the LHC: from standard model to new physics

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