Author: Publisher: ISBN: Category : Languages : en Pages : 5
Book Description
In this contribution, some of the recent QCD results on jet production from the CDF and D0 experiments in Run II of the Tevatron are discussed. In particular, results include cross section measurements for dijet and trijet production, study of jet substructure and measurements of W/Z+jets cross sections. The measurements are compared with the theoretical predictions. The QCD program at the Tevatron proton-antiproton collider revolves around the jet physics. Jets are collimated sprays of hadrons generated by the fragmentation of partons originating from the hard scattering. The measurements of jets production cross section at the Tevatron provide stringent test of perturbative QCD predictions, information on the strong coupling constant, [alpha]s, and constraints on proton parton distribution functions, PDFs. The deviations from the pQCD predictions could translate into a hint of new physics. In addition, these processes form sizable backgrounds to both, the Standard Model (SM) and beyond SM physics processes. Therefore, good understanding of jets production is essential to perform precise physics measurements or searches for new physics phenomena. In this contribution, a review of some recent QCD results from the CDF [1] and D0 [2] experiments is presented. Various analyses use proton-antiproton collision data from the Fermilab Tevatron at the center of mass energy √s = 1.96 TeV corresponding to integrated luminosities of 0.7 fb−1 to 8 fb−1. The results are corrected for the experimental effects and presented at the 'particle level'. The theory predictions are corrected for the hadronization and underlying effects which are obtained from the parton shower Monte Carlo (MC) simulations.
Author: Publisher: ISBN: Category : Languages : en Pages : 28
Book Description
Results are presented detailing the status of tests of perturbative QCD in hard parton-parton collisions generated by high energy collisions of protons and antiprotons at the Fermilab Collider. Recent data fro the CDF and DO experiments are compared to Next-to-Leading Order QCD calculations in hadronic jet production, prompt photon production, jet production in events with W bosons, and b-quark production.
Author: Publisher: ISBN: Category : Languages : en Pages : 30
Book Description
Abstract: Recent results of QCD studies from the CDF and D0 experiments at the Tevatron {bar p}p collider at Fermilab are presented. The inclusive jet cross section, the internal structure of jets, di-jet angular distributions, di-jet triple differential cross sections, and properties of multi-jet final states are studied and compared with NLO QCD predictions. The comparisons show good agreement between theoretical predictions and the experimental data in general. Some systematic disagreement between LO predictions and the data are observed in di-jet triple differential cross sections. Results of a rapidity gap study are also presented together with an upper limit on the gap fraction. In addition, the inclusive photon cross section and the di-photon cross sections are presented and compared with NLO QCD predictions.
Author: Kiran Joshi Publisher: ISBN: 9783319196541 Category : Languages : en Pages :
Book Description
This thesis contains new research in both experimental and theoretical particle physics, making important contributions in each. Two analyses of collision data from the ATLAS experiment at the LHC are presented, as well as two phenomenological studies of heavy coloured resonances that could be produced at the LHC. The first data analysis was the measurement of top quark-antiquark production with a veto on additional jet activity. As the first detector-corrected measurement of jet activity in top-antitop events it played an important role in constraining the theoretical modelling, and ultimately reduced these uncertainties for ATLAS's other top-quark measurements by a factor of two. The second data analysis was the measurement of Z+2jet production and the observation of the electroweak vector boson fusion (VBF) component. As the first observation of VBF at a hadron collider, this measurement demonstrated new techniques to reliably extract VBF processes and paved the way for future VBF Higgs measurements. The first phenomenological study developed a new technique for identifying the colour of heavy resonances produced in proton-proton collisions. As a by-product of this study an unexpected and previously unnoticed correlation was discovered between the probability of correctly identifying a high-energy top and the colour structure of the event it was produced in. The second phenomenological study explored this relationship in more detail, and could have important consequences for the identification of new particles that decay to top quarks.
Author: N. Dombey Publisher: Springer Science & Business Media ISBN: 1468490540 Category : Science Languages : en Pages : 570
Book Description
The Workshop on Radiative Corrections: Results and Perspectives was held at the University of Sussex in fine weather between July 9 and 14 1989. The Workshop was weIl timed: the day after its concluding session the first beam at LEP was circulated. The Original aims of the Workshop were twofold: first to review the existing theoretical work on electroweak radiative corrections in the light of the initial experiments at SLC and LEP, and to attempt to obtain a consensus on the best means of carrying out the calculations of the various processes. This aim became Working Group A on Renormalisation Schemes tor Electroweak Radiative Corrections. The second aim was to review the experimental implementation of radiative corrections and this became Working Group B. Here the problem was to obtain a consensus on the use of Monte Carlo event generators. At the time (March 1987) when Friedrich Dydak wrote to one of us (ND) to suggest a Workshop on the subject of electroweak radiative corrections to take place just before experiments at LEP were to begin, the main theoretical problem was that there was no agreement among theorists on the use of a specific renormalization scheme. Similarly, it was already becoming clear that it was going to be very difficult to compare the experimental results of different groups because they would use different event generators and experimental cuts of their data.
Author: John Campbell Publisher: Oxford University Press ISBN: 0191014990 Category : Science Languages : en Pages : 761
Book Description
The Black Book of Quantum Chromodynamics is an in-depth introduction to the particle physics of current and future experiments at particle accelerators. The book offers the reader an overview of practically all aspects of the strong interaction necessary to understand and appreciate modern particle phenomenology at the energy frontier. It assumes a working knowledge of quantum field theory at the level of introductory textbooks used for advanced undergraduate or in standard postgraduate lectures. The book expands this knowledge with an intuitive understanding of relevant physical concepts, an introduction to modern techniques, and their application to the phenomenology of the strong interaction at the highest energies. Aimed at graduate students and researchers, it also serves as a comprehensive reference for LHC experimenters and theorists. This book offers an exhaustive presentation of the technologies developed and used by practitioners in the field of fixed-order perturbation theory and an overview of results relevant for the ongoing research programme at the LHC. It includes an in-depth description of various analytic resummation techniques, which form the basis for our understanding of the QCD radiation pattern and how strong production processes manifest themselves in data, and a concise discussion of numerical resummation through parton showers, which form the basis of event generators for the simulation of LHC physics, and their matching and merging with fixed-order matrix elements. It also gives a detailed presentation of the physics behind the parton distribution functions, which are a necessary ingredient for every calculation relevant for physics at hadron colliders such as the LHC, and an introduction to non-perturbative aspects of the strong interaction, including inclusive observables such as total and elastic cross sections, and non-trivial effects such as multiple parton interactions and hadronization. The book concludes with a useful overview contextualising data from previous experiments such as the Tevatron and the Run I of the LHC which have shaped our understanding of QCD at hadron colliders.
Author: Publisher: ISBN: Category : Languages : en Pages :
Book Description
Four years after the shutdown of the Tevatron proton-antiproton collider, the two Tevatron experiments, CDF and DZero, continue producing important results that test the theory of the strong interaction, Quantum Chromodynamics (QCD). The experiments exploit the advantages of the data sample acquired during the Tevatron Run II, stemming from the unique pp initial state, the clean environment at the relatively low Tevatron instantaneous luminosities, and the good understanding of the data sample after many years of calibrations and optimizations. A summary of results using the full integrated luminosity is presented, focusing on measurements of prompt photon production, weak boson production associated with jets, and non-perturbative QCD processes.
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Author: Kiran Joshi
Author: J. Thanh Van Tran
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Author: N. Dombey
Author: John Campbell
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Author: Robert Plunkett