Download or read book Next to Leading Order Three Jet Production at Hadron Colliders written by and published by . This book was released on 1997 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: I present results from a next-to-leading order event generator of purely gluonic jet production. This calculation is the first step in the construction of a full next-to-leading order calculation of three jet production at hadron colliders. Several jet algorithms commonly used in experiments are implemented and their numerical stability is investigated. A numerical instability is found in the iterative cone algorithm which makes it inappropriate for use in fixed order calculations beyond leading order.
Download or read book Precise Predictions for W 3 Jet Production at Hadron Colliders written by and published by . This book was released on 2009 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report on the first next-to-leading order QCD computation of W + 3-jet production in hadronic collisions including all partonic subprocesses. We compare the results with CDF data from the Tevatron, and find excellent agreement. The renormalization and factorization scale dependence is reduced substantially compared to leading-order calculations. The required one-loop matrix elements are computed using on-shell methods, implemented in a numerical program, BlackHat. We use the SHERPA package to generate the real-emission contributions and to integrate the various contributions over phase space. We use a leading-color (large-N{sub c}) approximation for the virtual part, which we confirm in W + 1,2-jet production to be valid to within three percent. The present calculation demonstrates the utility of on-shell methods for computing next-to-leading-order corrections to processes important to physics analyses at the Large Hadron Collider.
Download or read book Next to Leading Order Corrections to W photon jet and W Z jet Production at Hadron Colliders written by Christoph Englert and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Next to Leading Order Predictions for W 3 Jet Distributions at Hadron Colliders written by and published by . This book was released on 2009 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present next-to-leading order QCD predictions for a variety of distributions in W + 3-jet production at both the Tevatron and the Large Hadron Collider. We include all subprocesses and incorporate the decay of the W boson into leptons. Our results are in excellent agreement with existing Tevatron data and provide the first quantitatively precise next-to-leading order predictions for the LHC. We include all terms in an expansion in the number of colors, confirming that the specific leading-color approximation used in our previous study is accurate to within three percent. The dependence of the cross section on renormalization and factorization scales is reduced significantly with respect to a leading-order calculation. We study different dynamical scale choices, and find that the total transverse energy is significantly better than choices used in previous phenomenological studies. We compute the one-loop matrix elements using on-shell methods, as numerically implemented in the BlackHat code. The remaining parts of the calculation, including generation of the real-emission contributions and integration over phase space, are handled by the SHERPA package.
Download or read book Jet Production at Hadron Colliders written by Teppo Tapani Jouttenus and published by . This book was released on 2012 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hadronic jets feature in many final states of interest in modern collider experiments. They form a significant Standard Model background for many proposed new physics processes and also probe QCD interactions at several different scales. At high energies incoming protons produce beam jets. Correctly accounting for the beam and central jets is critical to precise understanding of hadronic final states at the Large Hadron Collider. We study jet cross sections as a function of the shape of both beam and central jets. This work focuses on measuring jet mass but our methods can be applied to other jet shape variables as well. Measuring jet mass introduces additional scales to the collision process and these scales produce large logarithms that need to be resummed. Factorizing the cross section into hard, jet, beam, and soft functions enables such resummation. We begin by studying jet production at e + e- collisions in order to focus on the effects of jet algorithms. These results can be carried over to the more complicated case of hadron collisions. We use the Sterman-Weinberg algorithm as a specific example and derive an expression for the quark jet function. Turning to hadron colliders, we show how the N-jettiness event shape divides phase space into N +2 regions, each containing one central or beam jet. Thus, N-jettiness works as a jet algorithm. Using a geometric measure gives central jets with circular boundaries. We then give a factorization theorem for the cross section fully differential in the mass of each jet, and compute the corresponding soft function at next-to-leading order (NLO). We use a method of hemisphere decomposition, which can also be applied to calculate N-jet soft functions defined with other jet algorithms. Our calculation of the N-jettiness soft function provides the final missing ingredient to extend NLO cross sections to resunmmed predictions at next-to-next-to-leading logarithmic order. We study the production of an exclusive jet together with a Standard Model Higgs boson. Based on theoretical reasons and agreement between our calculation and data from the ATLAS collaboration, we argue that our results for the jet mass spectrum are a good approximation also for inclusive jet production and other hard processes.
Download or read book Gluonic Three Jet Production at Next to Leading Order written by and published by . This book was released on 1996 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: I report results from a next-to-leading order event generator of purely gluonic jet production. This calculation, performed in collaboration with Walter Giele, is the first step in the construction of a full next-to-leading order calculation of three jet production at hadron colliders.
Download or read book Jet Physics at the LHC written by Klaus Rabbertz and published by Springer. This book was released on 2016-10-11 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reviews the latest experimental results on jet physics from proton-proton collisons at the LHC. Jets allow to determine the strong coupling constant over a wide range of energies up the highest ones possible so far, and to constrain the gluon parton distribution of the proton, both of which are important uncertainties on theory predictions in general and for the Higgs boson in particular.A novel approach in this book is to categorize the examined quantities according to the types of absolute, ratio, or shape measurements and to explain in detail the advantages and differences. Including numerous illustrations and tables the physics message and impact of each observable is clearly elaborated.
Download or read book Next to leading Order Corrections to W jet W gamma jet and WZ jet Production at Hadron Colliders written by Christoph Englert and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Analytic S Matrix written by R. J. Eden and published by Cambridge University Press. This book was released on 2002-04-30 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: A theory of the S-Matrix, starting from physically plausible assumptions and looking at the mathematical consequences.
Download or read book Precise Predictions for W 4 Jet Production at the Large Hadron Collider written by and published by . This book was released on 2010 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the first next-to-leading order QCD results for W + 4-jet production at hadron colliders. Total cross sections, as well as distributions in the jet transverse momenta and in the total transverse energy HT, are provided for the initial LHC energy of (square root)s = 7 TeV. We use a leading-color approximation, known to be accurate to 3% for W production with fewer jets. The virtual matrix elements and the most complicated real-emission matrix elements are handled by the BlackHat library, based on on-shell methods. The remaining parts of the calculation, including the integration over phase space, are performed by the SHERPA package.
Download or read book From Actions To Answers Proceedings Of The 1989 Theoretical Advanced Study Institute In Elementary Particle Physics written by Thomas A Degrand and published by World Scientific. This book was released on 1990-04-01 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt: This School focussed on computation in theoretical particle physics. Accordingly, it had large components on collider phenomenology and lattice gauge theory. A number of lectures on current topics in modern mathematical physics (conformal field theory, quantum gravity, and sphalerons) were included.
Download or read book Dijet Angular Distributions in Proton Proton Collisions written by Nele Boelaert and published by Springer Science & Business Media. This book was released on 2011-10-26 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis is based on the first data from the Large Hadron Collider (LHC) at CERN. Its theme can be described as the classical Rutherford scattering experiment adapted to the LHC: measurement of scattering angles to search for new physics and substructure. At the LHC, colliding quarks and gluons exit the proton collisions as collimated particle showers, or jets. The thesis presents studies of the scattering angles of these jets. It includes a phenomenological study at the LHC design energy of 14 TeV, where a model of so-called large extra dimensions is used as a benchmark process for the sensitivity to new physics. The experimental result is the first measurement, made in 2010, by ATLAS, operating at the LHC start-up energy of 7 TeV. The result is compatible with the Standard Model and demonstrates how well the physics and the apparatus are understood. The first data is a tiny fraction of what will be accumulated in the coming years, and this study has set the stage for performing these measurements with confidence as the LHC accumulates luminosity and increases its energy, thereby probing smaller length scales.
Download or read book Hadron Collider Physics 2002 written by Martin Erdmann and published by Springer Science & Business Media. This book was released on 2003 with total page 572 pages. Available in PDF, EPUB and Kindle. Book excerpt: I Opening Review on Hadron-Collider Physics.- Hadron Colliders, the Standard Model, and Beyond.- 1 What is the Standard Model?.- 2 Hadron Colliders and the Standard Model.- 2.1 Precision electroweak.- 2.2 CKM.- 2.3 Top quark.- 2.4 Higgs boson.- 2.5 QCD.- 3 Beyond the Standard Model.- 3.1 Direct evidence.- 3.2 Indirect evidence.- References.- II Status of the Accelerators and Detectors.- Tevatron Collider Run II Status.- 1 Introduction.- 2 Overview.- 3 Run II Milestones.- 4 Parameters.- 5 Performance to Date.- 6 Accomplishments.- 6.1 Accomplishments: Helix Adjustments.- 6.2 Accomplishments: Antiproton Emittance.- 6.3 Accomplishments: Tevatron Injection Closure.- 7 Outstanding Issues.- 8 Future Prospects.- 9 Reliability.- 10 Summary.- 11 Acknowledgements.- Status of CDF II and Prospects for Run II.- 1 Introduction.- 2 The CDF II Detector and Trigger Upgrades.- 3 Physics Results and Prospects.- 4 Conclusions.- References.- Status of the D Detector.- 1 Introduction.- 2 Overview.- 3 Silicon Vertex Detector.- 4 Central Fiber Tracker.- 5 Calorimeters.- 6 Muon Detectors.- 7 Forward Proton Detectors.- 8 Trigger and Data Acquisition.- 9 Conclusions.- References.- III Standard Model Processes: Parton Luminosities, QCD Evolution.- The Proton Structure as Measured at HERA.- 1 Introduction.- 2 NC Cross Sections in the Complete Kinematic Plane.- 3 High-Q2 Measurements.- 4 Charged Current Measurements.- 5 Summary and Outlook.- References.- Global Fits of Parton Distributions.- 1 Introduction.- 2 Parton Uncertainties.- 2.1 Hessian (Error Matrix) approach.- 2.2 Offset method.- 2.3 Statistical approach.- 2.4 Lagrange multiplier method.- 2.5 Results.- 3 Theoretical Errors.- 3.1 Problems in the fit.- 3.2 Types of Theoretical Error, NNLO.- 3.3 Empirical approach.- 4 Conclusions.- References.- Low x Physics at HERA.- 1 Introduction.- 2 Formalism and Theory.- 3 Results.- 3.1 Inclusive measurements.- 3.2 Exclusive results.- 4 Summary.- References.- Saturation Effects in Hadronic Cross Sections.- 1 Introduction.- 2 The Loop-Loop Correlation Model.- 3 Saturation in Proton-Proton Scattering.- 4 Gluon Saturation.- 5 Conclusion.- References.- IV Standard Model Processes: QCD at High pt.- Progress in NNLO Calculations for Scattering Processes.- 1 Why NNLO Calculations are Important.- 1.1 Renormalisation scale uncertainty.- 1.2 Factorisation scale dependence.- 1.3 Jet algorithms.- 1.4 Transverse momentum of the incoming partons.- 1.5 Power corrections.- 1.6 The shape of the prediction.- 1.7 Parton densities at NNLO.- 2 Recent Progress in the Field.- 3 What Remains to be Done.- References.- Heavy Flavour Production at D .- 1 Introduction.- 2 b-production Cross-section.- 2.1 Muon and Jet Cross-section.- 2.2 b-tagging.- 3 J/? Cross-section.- 4 Other Measurements.- References.- Heavy Quark Production at CDF.- 1 Introduction.- 2 Beauty Production at CDF.- 2.1 CDF Run I results.- 2.2 Preliminary results from CDF Run II.- 3 Quarkonia Production at CDF.- 4 Charm Production at CDF.- 4.1 Run I results.- 4.2 Run II charm production cross-sections.- 5 Conclusion.- References.- Heavy Quark Production at HERA.- 1 Introduction.- 2 Open Charm Production.- 3 Charmonium.- 4 Beauty Production.- 5 Summary.- References.- Theoretical Developments on Hard QCD Processes at Colliders.- 1 Introduction.- 2 Heavy Quarks.- 2.1 Total Cross Sections.- 2.2 Transverse Momentum Distributions.- 2.3 Top Quark Spin Correlations.- 3 Jets.- 3.1 Jet Definitions.- 3.2 Precision Jet Physics.- 3.3 Multiparton Processes.- 4 Photons and Massive Gauge Bosons.- 4.1 Isolated Photons.- 4.2 Photon Pairs.- 4.3 Vector Boson and Higgs Production.- 4.4 Transverse Momentum Distributions.- 5 Conclusions and Outlook.- References.- Jet Production at CDF.- 1 Introduction.- 2 Inclusive Jet Production.- 3 Three-jet Production.- 4 Study of Jet Shapes in Run 2.- 5 Study of the Underlying Event.- 6 Study of W+Njet Production.- References.- Jet Algorithms at D .- 1 Introduction.- 2 The Measurement of Jets.- 3 Run I Co
Download or read book 97 QCD and High Energy Hadronic Interactions written by J. Thanh Van Tran and published by Atlantica Séguier Frontières. This book was released on 1997 with total page 690 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Multi jet Cross Sections at NLO with BlackHat and Sherpa written by and published by . This book was released on 2009 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this talk, we report on a recent next-to-leading order QCD calculation of the production of a W boson in association with three jets at hadron colliders. The computation is performed by combining two programs, BlackHat for the computation of the virtual one-loop matrix elements and Sherpa for the real emission part. The addition of NLO corrections greatly reduces the factorization and renormalization scale dependence of the theory prediction for this process. This result demonstrates the applicability of unitarity-based methods for hadron collider physics.
Download or read book Qcd Corrections And New Physics Proceedings Of The International Symposium written by Jiro Kodaira and published by World Scientific. This book was released on 1998-09-02 with total page 255 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses recent developments in both the theoretical and the experimental aspects of QCD. Its main goal is to establish precise predictions of the Standard Model in order to find clues to the discovery of New Physics.
Download or read book Frontiers in Particle Physics written by Jean-Marc Gérard and published by Springer Science & Business Media. This book was released on 2013-12-01 with total page 461 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of a NATO ASI held in Cargese, France, August 1-13, 1994
