Author: Shreyasi Acharya
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Z-boson Production in P-Pb Collisions at √sNN
Study of Z Boson Production in PPb Collisions at {u221A}sNN
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 22
Book Description
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.
Publisher:
ISBN:
Category :
Languages : en
Pages : 22
Book Description
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.
Study of Z Boson Production in PPb Collisions at √sNN
Measurement of the Associated Production of Z Bosons and Jets in P-pbar Collisions at the Tevatron
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 111
Book Description
Higher order QCD corrections to W and Z boson production do not only manifest themselves in the generation of high transverse momenta of the weak bosons, but these QCD effects become directly visible in the production of jets in association with the weak bosons. Studying these processes is not only interesting from the perspective of testing perturbative QCD, but also to constrain a major background to many Standard Model (SM) of non-SM physics signals, e.g. top pair and single top production, searchers for the Higgs boson, leptoquarks and supersymmetric particles. This thesis describes a measurement of Z/[gamma]* + jets production in p$\bar{p}$ collisions at √s = 1.96 TeV in the decay channel Z/[gamma]* → [mu]+[mu]-. An integrated luminosity of L≈ 1fb-1 collected by the D0 detector at the Tevatron between August 2002 and February 2006 has been used. Differential production cross sections as function of the transverse energy of the first, second and third leading jet are measured. The distributions are corrected for acceptance and migration effects back to hadron level using an iterative unfolding method. Comparison of the measured cross sections to event generators, which include part of the higher order corrections are presented.
Publisher:
ISBN:
Category :
Languages : en
Pages : 111
Book Description
Higher order QCD corrections to W and Z boson production do not only manifest themselves in the generation of high transverse momenta of the weak bosons, but these QCD effects become directly visible in the production of jets in association with the weak bosons. Studying these processes is not only interesting from the perspective of testing perturbative QCD, but also to constrain a major background to many Standard Model (SM) of non-SM physics signals, e.g. top pair and single top production, searchers for the Higgs boson, leptoquarks and supersymmetric particles. This thesis describes a measurement of Z/[gamma]* + jets production in p$\bar{p}$ collisions at √s = 1.96 TeV in the decay channel Z/[gamma]* → [mu]+[mu]-. An integrated luminosity of L≈ 1fb-1 collected by the D0 detector at the Tevatron between August 2002 and February 2006 has been used. Differential production cross sections as function of the transverse energy of the first, second and third leading jet are measured. The distributions are corrected for acceptance and migration effects back to hadron level using an iterative unfolding method. Comparison of the measured cross sections to event generators, which include part of the higher order corrections are presented.
Measurement of W Boson Production in Pb+Pb Collisions at 5.02 TeV with the ATLAS Detector
Aspects of Z Boson Production at Higher Orders at Hadron Colliders
Search for the Production of the Standard Model Z Boson in Association with W Boson in P - Anti-p Collisions at 1.96 TeV Center of Mass Energy
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 162
Book Description
The search for the production of the Standard Model Z boson in association with a W boson is motivated and discussed. This is performed using 4.3 fb−1 of Tevatron Run II data collected with the CDF detector in (square root)s = 1.96 TeV proton anti-proton collisions. This is a signature-based analysis where the W boson decays semileptonically into a high-P{sub T} electron or muon plus a neutrino, and where the Z boson decays into two b quark jets (b-jets). We increase the signal-to-background ratio by identifying the b-quarks in the jets with a new neural network-based algorithm. Another neural network then uses kinematic information to distinguish WZ to further increase the signal-to-background ratio. Since our sensitivity is still not enough to achieve an observation, we set a 95% Confidence Level upper limit on the product of the WZ production cross section and its branching fraction to the decay products specified above, and express it as a ratio to the theoretical Standard Model prediction. The resulting limit is 3.9 x SM (3.9 x SM expected).
Publisher:
ISBN:
Category :
Languages : en
Pages : 162
Book Description
The search for the production of the Standard Model Z boson in association with a W boson is motivated and discussed. This is performed using 4.3 fb−1 of Tevatron Run II data collected with the CDF detector in (square root)s = 1.96 TeV proton anti-proton collisions. This is a signature-based analysis where the W boson decays semileptonically into a high-P{sub T} electron or muon plus a neutrino, and where the Z boson decays into two b quark jets (b-jets). We increase the signal-to-background ratio by identifying the b-quarks in the jets with a new neural network-based algorithm. Another neural network then uses kinematic information to distinguish WZ to further increase the signal-to-background ratio. Since our sensitivity is still not enough to achieve an observation, we set a 95% Confidence Level upper limit on the product of the WZ production cross section and its branching fraction to the decay products specified above, and express it as a ratio to the theoretical Standard Model prediction. The resulting limit is 3.9 x SM (3.9 x SM expected).
Measurements of the Associated Production of a Z Boson and B Jets in Pp Collisions at $\sqrt{s}$
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Measurements of the associated production of a Z boson with at least one jet originating from a b quark in proton-proton collisions at $\sqrt{s}$ = 8 TeV are presented. Differential cross sections are measured with data collected by the CMS experiment corresponding to an integrated luminosity of 19.8 inverse femtobarns. Z bosons are reconstructed through their decays to electrons and muons. Cross sections are measured as a function of observables characterizing the kinematics of the b jet and the Z boson. Ratios of differential cross sections for the associated production with at least one b jet to the associated production with any jet are also presented. The production of a Z boson with two b jets is investigated, and differential cross sections are measured for the dijet system. Results are compared to theoretical predictions, testing two different flavour schemes for the choice of initial-state partons.
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Measurements of the associated production of a Z boson with at least one jet originating from a b quark in proton-proton collisions at $\sqrt{s}$ = 8 TeV are presented. Differential cross sections are measured with data collected by the CMS experiment corresponding to an integrated luminosity of 19.8 inverse femtobarns. Z bosons are reconstructed through their decays to electrons and muons. Cross sections are measured as a function of observables characterizing the kinematics of the b jet and the Z boson. Ratios of differential cross sections for the associated production with at least one b jet to the associated production with any jet are also presented. The production of a Z boson with two b jets is investigated, and differential cross sections are measured for the dijet system. Results are compared to theoretical predictions, testing two different flavour schemes for the choice of initial-state partons.