Our first study of W boson production in pPb collisions is presented, for bosons decaying to a muon or electron, and a neutrino. The measurements are based on a data sample corresponding to an integrated luminosity of 34.6 nb-1 at a nucleon-nucleon centre-of-mass energy of [arrow]"NN= 5.02 TeV, collected by the CMS experiment. The W boson differential cross sections, lepton charge asymmetry, and forward-backward asymmetries are measured for leptons of transverse momentum exceeding 25 GeV/c, and as a function of the lepton pseudorapidity in the.

The production of Z bosons in pPb collisions at √sNN = 5.02TeV is studied by the CMS experiment via the electron and muon decay channels. The inclusive cross section is compared to pp collision predictions, and found to scale with the number of elementary nucleon-nucleon collisions. The differential cross sections as a function of the Z boson rapidity and transverse momentum are measured. Though they are found to be consistent within uncertainty with theoretical predictions both with and without nuclear effects, the forward-backward asymmetry suggests the presence of nuclear effects at large rapidities. These results provide new data for constraining nuclear parton distribution functions.

The production cross sections of the B+, B0, and B0s mesons, and of their charge conjugates, are measured via exclusive hadronic decays in pPb collisions at the center-of-mass energy √sNN = 5.02 TeV with the CMS detector at the CERN LHC. We used the dataset for this analysis and it corresponds to an integrated luminosity of 34.6 nb-1. The production cross sections are measured in the transverse momentum range between 10 and 60 GeV/c. No significant modification is observed compared to proton-proton perturbative QCD calculations scaled by the number of incoherent nucleon-nucleon collisions. Furthermore, these results provide a baseline for the study of in-medium b quark energy loss in PbPb collisions.

Zusammenfassung: In this thesis, measurements of the W boson pair production cross section in proton-proton collisions at a centre-of-mass energy of 8 TeV are presented. A dataset corresponding to an integrated luminosity of 22.3 /fb recorded by the ATLAS experiment in the year 2012 is used. The W bosons are identified by their decay products of exactly two leptons with opposite electrical charge, electrons or muons, and missing transverse momentum induced by their corresponding neutrinos. First, a measurement restricted to final states without hadronic jets is presented and differential fiducial cross sections, total cross sections and limits on anomalous triple gauge boson couplings are obtained. A second measurement of the fiducial cross section in association with exactly one hadronic jet is presented. The ratio of fiducial cross sections for different jet multiplicities is reported and the combined fiducial cross section is extrapolated to the total phase space.

A search for Z bosons in the mu+̂mu-̂ decay channel has been performed in PbPb collisions at a nucleon-nucleon centre of mass energy = 2.76 TeV with the CMS detector at the LHC, in a 7.2 inverse microbarn data sample. The number of opposite-sign muon pairs observed in the 60--120 GeV/c2̂ invariant mass range is 39, corresponding to a yield per unit of rapidity (y) and per minimum bias event of (33.8 +/- 5.5 (stat) +/- 4.4 (syst)) 10{̂-8}, in the.

The cross section for the production and subsequent decay of the W Intermediate Vector boson to electron and neutrino has been measured in .sqrt.s = 1.8 TeV /bar p/p collisions using the CDF Collider Detector at Fermilab. For this measurement, W events were identified from the large missing transverse energy associated with the unseen neutrino and an electromagnetic cluster passing rather loose electron criteria. 22 events passing the selection missing transverse energy greater than 25 GeV and electron transverse energy greater than 15 GeV were observed in a sample of 25nb/sup /minus/1/ yielding a sigma /center dot/ B = 2.6 ± 0.6 ± 0.5nb. This report agrees well with a parallel analysis based primarily on the identification of isolated electron and is in excellent agreement with theoretical predictions. 12 refs., 7 figs.

The production cross section of a W boson in association with two b jets is measured using a sample of proton-proton collisions at $ \sqrt{s} = $ 8 TeV collected by the CMS experiment at the CERN LHC. The data sample corresponds to an integrated luminosity of 19.8 fb$^{-1}$. The W bosons are reconstructed via their leptonic decays, $ \mathrm{ W }\to\ell\nu $, where $\ell=\mu$ or $\mathrm{ e }$. The fiducial region studied contains exactly one lepton with transverse momentum $ p_{\mathrm{T}}^{\ell}> $ 30 GeV and pseudorapidity $

Spectra of identified charged hadrons are measured in pPb collisions with the CMS detector at the LHC at sqrt(sNN) = 5.02 TeV. Charged pions, kaons, and protons in the transverse-momentum range pt approximately 0.1-1.7 GeV and laboratory rapidity abs(y)

"From 2015 to 2018, the Large Hadron Collider (LHC) collided protons at an unprecedented centre of mass energy of √s = 13 TeV. The ATLAS detector recorded an integrated luminosity of 139 fb−1 of these collisions hence offering an unprecedented opportunity to test the Standard Model (SM) of particle physics by measuring predicted but yet unobserved rare processes. The tri-boson W[gamma][gamma] production is one of these unobserved processes. Its sensitivity to the electroweak trilinear and quartic gauge couplings make it a great probe of new physics phenomena as Beyond Standard Model processes could affectthe effective strength of these couplings. This thesis presents the study of the W[gamma][gamma] process. Backgrounds are estimated from a combination of Monte Carlo (MC) simulations and data-driven techniques. The dominant source of background to the search for W[gamma][gamma] production are jets being misidentified as photons. The advanced data-driven technique used to estimate this background is presented in details. Finally thorough examination of the systematic uncertainties affecting the measurement of the W[gamma][gamma] production cross-section are presented. Taking into account all statistical and systematic uncertainties, the expected statistical significance of the measurement is of 5.1 [delta] for the differential measurement and 7.8 [delta] for the total cross-section"--