The Underlying Event in Hard Scattering Processes

The Underlying Event in Hard Scattering Processes
Author: Richard D. Field
Publisher:
Total Pages: 22
Release: 2002
Genre: Jets (Nuclear physics)
ISBN:

We study the behavior of the "underlying event" in hard scattering proton-antiproton collisions at 1.8 TeV and compare with the QCD Monte-Carlo models. The "underlying event" is everything except the two outgoing hard scattered "jets" and receives contributions from the "beam-beam remnants" plus initial and final-state radiation. The data indicate that neither ISAJET or HERWIG produce enough charged particles (with pt > 0.5 GeV /c) from the "beam-beam remnant" component and that ISAJET produces too many charged particles from initial-state radiation. PYTHIA which uses multiple parton scattering to enhance the "underlying event" does the best job describing the data.

The Underlying Event in Hard Scattering Processes

The Underlying Event in Hard Scattering Processes
Author:
Publisher:
Total Pages: 413
Release: 2002
Genre:
ISBN:

The authors study the behavior of the underlying event in hard scattering proton-antiproton collisions at 1.8 TeV and compare with the QCD Monte-Carlo models. The underlying event is everything except the two outgoing hard scattered jets and receives contributions from the beam-beam remnants plus initial and final-state radiation. The data indicate that neither ISAJET or HERWIG produce enough charged particles (with p{sub T}> 0.5 GeV/c) from the beam-beam remnant component and that ISAJET produces too many charged particles from initial-state radiation. PYTHIA which uses multiple parton scattering to enhance the underlying event does the best job describing the data.

QCD Hard Hadronic Processes

QCD Hard Hadronic Processes
Author: Bradley Cox
Publisher: Springer Science & Business Media
Total Pages: 548
Release: 2012-12-06
Genre: Science
ISBN: 1468488422

The Advanced Research Workshop on QeD Hard Hadronic Processes was held on 8-13 October 1987 at Hotel on the Cay, St. Croix, U. S. Virgin Islands. The underlying theme of the workshop, the first in a series, was an examination, both theoretical and experimental, of the state of understanding of Quantum Chromodynamics. Because of the pervasiveness of the strong interactions in all aspects of high energy physics, QCD is central to many problems in elementary particle physics. Therefore, this workshop was organized to provide a forum in which the theory Quantum Chromodynamics cou 1 d be confronted with experi ment. The workshop was organ i zed in four sessions, each of which concentrated on a major experimental arena in which a hard QCD process can be measured experimentally. A fifth session was rlevoted to global issues which effect all QCD processes. Each session began with a survey of the theoretical developments in the particular area and concluded with a round table which discussed the various information presented in the course of the discussions. A session of the workshop was devoted to the direct production of high transverse momentum photons in hadronic interactions. Data from several experiments, either completed or in progress at CERN (NA3, NA24, WA70, UA6, CCOR, R806, AFS, RllO, UA1 and UA2), were di scussed and the prospects for two new upcomi ng experi ments from Fermil ab (E-705, E-706) were presented.

Photon Physics at the LHC

Photon Physics at the LHC
Author: Michael Hance
Publisher: Springer Science & Business Media
Total Pages: 152
Release: 2012-11-08
Genre: Science
ISBN: 3642330622

This thesis reports on the first studies of Standard Model photon production at the Large Hadron Collider (LHC) using the ATLAS detector. Standard Model photon production is a large background in the search for Higgs bosons decaying into photon pairs, and is thus critical to understand. The thesis explains the techniques used to reconstruct and identify photon candidates using the ATLAS detector, and describes a measurement of the production cross section for isolated prompt photons. The thesis also describes a search for the Higgs boson in which the analysis techniques used in the measurement are exploited to reduce and estimate non-prompt backgrounds in diphoton events.

Quantum Chromodynamics

Quantum Chromodynamics
Author: Günther Dissertori
Publisher: Oxford University Press
Total Pages: 558
Release: 2003
Genre: Language Arts & Disciplines
ISBN: 0198505728

This is a new text on Quantum Chromodynamics, the theory of the strong force between quarks, the fundamental building blocks of nuclear matter. Although the focus is on experiments, the text also includes anextensive theoretical introduction to the field as well as many exercises with solutions explained in detail.

New Aspects of High-Energy Proton-Proton Collisions

New Aspects of High-Energy Proton-Proton Collisions
Author: A. Ali
Publisher: Springer Science & Business Media
Total Pages: 437
Release: 2012-12-06
Genre: Science
ISBN: 1461595401

Articles focus on the planned European proton-proton collider, and concentrate on physics issues, rather than the more technical concerns addressed in the three previous workshops. The use of energies much higher than those of the American Superconducting Super Collider is featured. Topics include reviews of current projects, hadron collisions, lep

Multiple Parton Interactions at the LHC

Multiple Parton Interactions at the LHC
Author: Paolo Bartalini
Publisher: World Scientific Publishing
Total Pages: 472
Release: 2018-11-08
Genre: Science
ISBN: 981322777X

Many high-energy collider experiments (including the current Large Hadron Collider at CERN) involve the collision of hadrons. Hadrons are composite particles consisting of partons (quarks and gluons), and this means that in any hadron–hadron collision there will typically be multiple collisions of the constituents — i.e. multiple parton interactions (MPI). Understanding the nature of the MPI is important in terms of searching for new physics in the products of the scatters, and also in its own right to gain a greater understanding of hadron structure. This book aims at providing a pedagogical introduction and a comprehensive review of different research lines linked by an involvement of MPI phenomena. It is written by pioneers as well as young leading scientists, and reviews both experimental findings and theoretical developments, discussing also the remaining open issues.

Searches for Dijet Resonances

Searches for Dijet Resonances
Author: Lydia Audrey Beresford
Publisher: Springer
Total Pages: 175
Release: 2018-09-04
Genre: Science
ISBN: 331997520X

This book addresses one of the most intriguing mysteries of our universe: the nature of dark matter. The results presented here mark a significant and substantial contribution to the search for new physics, in particular for new particles that couple to dark matter. The first analysis presented is a search for heavy new particles that decay into pairs of hadronic jets (dijets). This pioneering analysis explores unprecedented dijet invariant masses, reaching nearly 7 TeV, and sets constraints on several important new physics models. The two subsequent analyses focus on the difficult low dijet mass region, down to 200 GeV, and employ a novel technique to efficiently gather low-mass dijet events. The results of these analyses transcend the long-standing constraints on dark matter mediator particles set by several existing experiments.