Description and performance of track and primary-vertex reconstruction with the CMS tracker

A description is provided of the software algorithms developed for the CMS tracker both for reconstructing charged-particle trajectories in proton-proton interactions and for using the resulting tracks to estimate the positions of the LHC luminous region and individual primary-interaction vertices. Despite the very hostile environment at the LHC, the performance obtained with these algorithms is found to be excellent. For t (t) over bar events under typical 2011 pileup conditions, the average track-reconstruction efficiency for promptly-produced charged particles with transverse momenta of p(T) > 0.9GeV is 94% for pseudorapidities of vertical bar eta vertical bar < 0.9 and 85% for 0.9 < vertical bar eta vertical bar < 2.5. The inefficiency is caused mainly by hadrons that undergo nuclear interactions in the tracker material. For isolated muons, the corresponding efficiencies are essentially 100%. For isolated muons of p(T) = 100GeV emitted at vertical bar eta vertical bar < 1.4, the resolutions are approximately 2.8% in p(T), and respectively, 10 m m and 30 mu m in the transverse and longitudinal impact parameters. The position resolution achieved for reconstructed primary vertices that correspond to interesting pp collisions is 10-12 mu m in each of the three spatial dimensions. The tracking and vertexing software is fast and flexible, and easily adaptable to other functions, such as fast tracking for the trigger, or dedicated tracking for electrons that takes into account bremsstrahlung.

Measurement of jet fragmentation in PbPb and pp collisions at root s(NN)=2.76 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Measurement of the muon charge asymmetry in inclusive pp -> W plus X production at root s=7 TeV and an improved determination of light parton distribution functions

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for jet extinction in the inclusive jet-p(T) spectrum from proton-proton collisions at root s=8 TeV

The first search at the LHC for the extinction of QCD jet production is presented, using data collected with the CMS detector corresponding to an integrated luminosity of 10.7 fb-1 of proton-proton collisions at a center-of-mass energy of 8 TeV. The extinction model studied in this analysis is motivated by the search for signatures of strong gravity at the TeV scale (terascale gravity) and assumes the existence of string couplings in the strong-coupling limit. In this limit, the string model predicts the suppression of all high-transverse-momentum standard model processes, including jet production, beyond a certain energy scale. To test this prediction, the measured transverse-momentum spectrum is compared to the theoretical prediction of the standard model. No significant deficit of events is found at high transverse momentum. A 95% confidence level lower limit of 3.3 TeV is set on the extinction mass scale.

Search for WW gamma and WZ gamma production and constraints on anomalous quartic gauge couplings in pp collisions at root s=8 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Measurement of the ratio of inclusive jet cross sections using the anti-k(T) algorithm with radius parameters R=0.5 and 0.7 in pp collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Searches for electroweak neutralino and chargino production in channels with Higgs, Z, and W bosons in pp collisions at 8 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for supersymmetry with razor variables in pp collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evidence of b-Jet Quenching in PbPb Collisions at root S-NN=2.76 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Studies of dijet transverse momentum balance and pseudorapidity distributions in pPb collisions at root s(NN)=5.02 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Measurement of WZ and ZZ production in pp collisions at in final states with b-tagged jets

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for invisible decays of Higgs bosons in the vector boson fusion and associated ZH production modes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Measurement of jet multiplicity distributions in t(t)over-bar production in pp collisions at root s=7TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Observation of the diphoton decay of the Higgs boson and measurement of its properties

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Contação de histórias e educação crítica: uma proposta didática

This proposal offers a possibility of approximation of mathematical knowledge at the prospect of Critical Education defended by researchers such as Ole Skovsmose and Paulo Freire. Using storytelling as a methodological resource is intended to develop an activity that allows students to think critically about real-life situations that have democratic questions as ground. The research is part of the branch of mathematics concerned with the education goals of teaching mathematics in basic education. We discuss the relevance of an educational process that enables the development of a democratic competence in the first years of primary education by showing students that their classroom can and should be seen as a community, where everyone has rights and duties. The interpretation and understanding of real situations can be something very complex and uninteresting for students of that age, looking for an attractive feature such as storytelling, which is based on the tendency of Reading and Writing in Mathematics, proposed by Nacarato and Lopes; Cardoso and Fonseca. Adopting a phenomenological attitude in the research seeks to understand if the storytelling can contribute to the formation of the critical student. Assuming this perspective has developed a didactic sequence from the story 'o que os olhos não vêem' from writer Ruth Rocha. The student's writing, favored by the proposed sequence, subsidizes the understanding of their thinking and acting on the democratic situations