2,071 research outputs found
Search for Heavy Boson Resonances in Final States with a W or Z Boson and a Photon Using 139 \fb of Proton-Proton Collision Data at sqrt(s) = 13 TeV Collected with the ATLAS
No full textThis thesis presents a search for boson resonances that decay into an energetic photon and the Standard Model's W or Z boson: and . The dataset used for the measurement was collected at the CERN Large Hadron Collider during a run period from 2015 to 2018.
The proton-proton collision center-of-mass energy was 13 TeV with a useful integrated luminosity recorded using the ATLAS detector of 139 \fb.
New particle identification techniques are employed, and event selection criteria are optimized to improve the search sensitivity.
No significant deviations from the Standard Model predictions are observed over a and mass range from 1.0 to 6.8 TeV.
The data are used to set limits with 95\% confidence level on the production cross section of massive bosons that are predicted by various extensions of the Standard Model's theory of elementary particles.</p
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Dijet production from {bar p}p collisions at 1.8 TeV
No full textThe production properties of dijets from {ital p{anti p}} collisions at {radical}{ital s} = 1.8 TeV have been studied using the Collider Detector at Fermilab. This report presents an analysis of the dijet angular distributions using 106 pb{sup -1} of data collected during Run I of the Tevatron Collider. The measured angular distributions agree with next-to-leading order QCD predictions in five dijet invariant mass regions with average dijet mass varying from 263 to 698 GeV/c{sup 2}. The predicted angular distributions are relatively insensitive to parton distribution functions, and therefore these data can be used to put limits on energy scale parameters used to describe contact interactions. For a model with only up and down quarks composite, the data exclude at 95% confidence level a contact interaction scale {Lambda}{sub {ital ud}}{sup +} {<=} 1.6 TeV of {Lambda}{sub {ital ud}}{sup -} {<=} 1.4 TeV
Recent electroweak results from ATLAS
No full textATLAS measurements of multi-boson production processes involving combinations of up to three W and Z bosons and isolated photons are presented. The cross sections are measured inclusively and differentially as a function of different kinematic quantities. First measurements if di-boson cross sections at a pp center of mass energy of 13 TeV are presented. Measurements are compared to Standard Model expectations and limits on anomalous triple and quartic qauge- boson couplings are summarized
Search for New Resonance X->W Gamma and Standard Model W Gamma Production Using Deep Learning Techniques
No full textThe Standard Model is by far the most encompassing physics theory. With the recent discovery of the Higgs Boson, the Standard Model has performed extremely well when confronted with experimental data. However, the theory is intrinsically not complete. Extensions of the Standard Model predict new resonances decaying to a W boson and a photon. This thesis presents a search for such resonances produced in proton-proton collisions at 13 TeV using a dataset with an integrated luminosity of 36.1 fb−1 collected by the ATLAS detector at the Large Hadron Collider. The W bosons are identified through their hadronic decay channels. The data are found to be consistent with the expected background in the entire mass range investigated. Upper limits are set on the production cross section times decay branching ratio to W + gamma of new resonances with mass between 1.0 and 6.8 TeV.
The second part of this thesis looks at the extraction of the Standard Model W + gamma production. The main background noise for the extraction comes from the Standard Model production of gamma and jets. In order to streamline and improve the accuracy of the event filtering process, this thesis developed a deep neural net classifier to identify signal and background decay products and improved the signal to noise ratio
Measurement of Z +γ Production and Search for Anomalous Triple Gauge Couplings in Proton-antiproton Collisions at √S = 1.96 Tev
No full textWe present a measurement of ppbar->Zγ + X -> e+e-γ + X production using proton-antiproton collision data collected at the Collider Detector at Fermilab at a center of mass energy of 1.96 TeV. Zγ production provides a direct test of the triple neutral gauge couplings. A measurement of Zγ production cross section and search for anomalous ZZγ and Zγγ couplings are presented.
The data presented are from 1.1 fb-1 of ppbar integrated luminosity collected at the CDF Detector. Electrons from Z decays are selected with Et > 20 GeV. Photons (Et > 7 GeV) are required to be well-separated from the electrons. There are 390 eeγ candidate events found with 1.1 fb-1 of data, compared to the SM prediction of 375.3 à ± 25.2 events. The Standard Model prediction for the cross section for ppbar-> e+e-γ + X
production at √s = 1.96 TeV is 4.5 à ± 0.4 pb. The measured cross section is 4.7 à ± 0.6 pb. The cross section and kinematic distributions of the eeγ events are in good agreement with theoretical predictions.
Limits on the ZZγ and Zγγ couplings are extracted using the photon Et distribution of eeγ events with Meeγ > 100 GeV/c2. These are the first limits measured using CDF Run II data. These limits provide important test of the interaction of the photon and the Z boson
Gauge Boson Coupling Measurements in Final States of W Boson Produced with Additional Photons with The ATLAS Detector
No full textA first measurement of pp -> Wγγ+X production cross section and the process of vector boson scattering producing Wγ, using the 20.3fb-1 dataset collected by the ATLAS detector from the proton-proton collisions at the Large Hadron Collide (LHC) located in CERN, are presented in this thesis.</p
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Di-boson physics at the Tevatron
No full textA summary is presented of recent measurements of di-boson production at the Tevatron. The results from the CDF and D0 experiments are based upon 130-320 pb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV. The W{gamma}, Z{gamma}, WW, and WZ production properties are compared to Standard Model predictions, and limits extracted for anomalous triple gauge couplings
Farthest-North Collegian, Vol. 08, No. 08 (April 1930)
No full textOn the World's Great Northern Highway -- Annual Meeting Regents Held at Alaska College -- Parting Guest is Speeded at Recent Yak Stew Party -- New World in Making Seen in Recent Visit of Men of Four Nations : Position of the Alaska College on the Direct Northern Route is One to be Prized -- Smith Suggests Rammed Earth as House Material -- Danish Novelist Tells Story of Greenland Trip -- Alaska's Petroleum -- Five Curricula Open to Students Electing Business -- George R. Goshaw Suggests a Study of Certain Northern Fur-Bearers -- Peat Production Likely to Become Interior Industry -- College Secures Reprint of First Alaska Newspaper -- "Alaskan" Name New Coast Flyer -- Alaska Trappers Furnish Material for Wide Market -- Alaska's Winners : The Salmon Industry -- Uncle Sam's Railroad -- The Business End -- Business Sets the Pace -- Unique Transport Methods -- Years See Changes in Fairbanks and in Business Scale -- College Players Entertain Many at the Empres
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