Measurements of differential production cross sections for a Z boson in association with jets in pp collisions at root s=8 TeV

Peer reviewe

Charged-particle nuclear modification factors in PbPb and pPb collisions at √=sNN=5.02 TeV

The spectra of charged particles produced within the pseudorapidity window |η| < 1 at √ sNN = 5.02 TeV are measured using 404 µb −1 of PbPb and 27.4 pb−1 of pp data collected by the CMS detector at the LHC in 2015. The spectra are presented over the transverse momentum ranges spanning 0.5 < pT < 400 GeV in pp and 0.7 < pT < 400 GeV in PbPb collisions. The corresponding nuclear modification factor, RAA, is measured in bins of collision centrality. The RAA in the 5% most central collisions shows a maximal suppression by a factor of 7–8 in the pT region of 6–9 GeV. This dip is followed by an increase, which continues up to the highest pT measured, and approaches unity in the vicinity of pT = 200 GeV. The RAA is compared to theoretical predictions and earlier experimental results at lower collision energies. The newly measured pp spectrum is combined with the pPb spectrum previously published by the CMS collaboration to construct the pPb nuclear modification factor, RpA, up to 120 GeV. For pT > 20 GeV, RpA exhibits weak momentum dependence and shows a moderate enhancement above unity

Estudos Cinéticos, Isotérmicos e Termodinâmicos Referentes à Adsorção do Corante Têxtil Rubi 2G Dianix sobre Quitosana.

Kinetic, Isothermal and Thermodynamic Studies from Adsorption of Textile Dye Ruby 2G Dianix onto Chitosan. Kinetic, isothermal and thermodynamic equilibrium experiments from adsorption of textile dye ruby 2G Dianix onto chitosan in aqueous medium were studied, as well as biopolymer characterization. Bath adsorptions experiments were realized and the pH results indicated the best range adsorption is between 4,0 and 6,0. The kinetic reaction suggests a second order rate law and the isotherm results agree with the Langmuir model. The thermodynamic parameters (ΔGº, ΔHº and ΔSº) also are presented in this work

Isotermas de Adsorção de Diferentes Corantes Têxteis sobre Quitosana

Adsorption isotherm of some textile dyes onto chitosan. The biopolymer chitosan was employed as adsorbent material to remove some textile dyes (blue R 160% Rcmazol, ru.bine S-2G Dianix, turquoise G 133% Remazol, red RB gran 133% Remazol and brilliant violet 5R Remawl) from aqueous solutions at pH 6.0. The obtained isothenns pointed out the following adsorption capacity sequence: (mg.g-I ): blue (952.4) > violet (699.3) > red (418.4) > rubine (294.1) > turquoise (245.1). The experimental data for all textile dyes studied showed that the equilibrium isotherms correlated very well with the Langmuir isotherm equation

Search for dark matter produced in association with heavy-flavor quark pairs in proton-proton collisions at √s=13TeV

A search is presented for an excess of events with heavy-flavor quark pairs (tt¯ and bb¯) and a large imbalance in transverse momentum in data from proton–proton collisions at a center-of-mass energy of 13TeV. The data correspond to an integrated luminosity of 2.2fb-1 collected with the CMS detector at the CERN LHC. No deviations are observed with respect to standard model predictions. The results are used in the first interpretation of dark matter production in tt¯ and bb¯ final states in a simplified model. This analysis is also the first to perform a statistical combination of searches for dark matter produced with different heavy-flavor final states. The combination provides exclusions that are stronger than those achieved with individual heavy-flavor final states. © 2017, CERN for the benefit of the CMS collaboration

Measurement of differential cross sections for Z boson production in association with jets in proton-proton collisions at √s=13TeV

The production of a Z boson, decaying to two charged leptons, in association with jets in proton-proton collisions at a centre-of-mass energy of 13TeV is measured. Data recorded with the CMS detector at the LHC are used that correspond to an integrated luminosity of 2.19fb-1. The cross section is measured as a function of the jet multiplicity and its dependence on the transverse momentum of the Z boson, the jet kinematic variables (transverse momentum and rapidity), the scalar sum of the jet momenta, which quantifies the hadronic activity, and the balance in transverse momentum between the reconstructed jet recoil and the Z boson. The measurements are compared with predictions from four different calculations. The first two merge matrix elements with different parton multiplicities in the final state and parton showering, one of which includes one-loop corrections. The third is a fixed-order calculation with next-to-next-to-leading order accuracy for the process with a Z boson and one parton in the final state. The fourth combines the fully differential next-to-next-to-leading order calculation of the process with no parton in the final state with next-to-next-to-leading logarithm resummation and parton showering. © 2018, CERN for the benefit of the CMS collaboration