Download or read book Partonic Calculation of the Two photon Exchange Contribution to Elastic Electron proton Scattering at Large Momentum Transfer written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We estimate the two-photon exchange contribution to elastic electron-proton scattering at large momentum transfer through the scattering off a parton in the proton. We relate the process on the nucleon to the generalized parton distributions which also enter in other wide angle scattering processes. We find that when taking the polarization transfer determinations of the form factors as input, adding in the 2 photon correction, does reproduce the Rosenbluth data.
Download or read book The Two Photon Exchange Contribution to Elastic Electron Nucleon Scattering at Large Momentum Transfer written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We estimate the two-photon exchange contribution to elastic electron-proton scattering at large momentum transfer by using a quark-parton representation of virtual Compton scattering. We thus can relate the two-photon exchange amplitude to the generalized parton distributions which also enter in other wide angle scattering processes. We find that the interference of one- and two-photon exchange contribution is able to substantially resolve the difference between electric form factor measurements from Rosenbluth and polarization transfer experiments. Two-photon exchange has additional consequences which could be experimentally observed, including nonzero polarization effects and a positron-proton/electron-proton scattering asymmetry. The predicted Rosenbluth plot is no longer precisely linear; it acquires a measurable curvature, particularly at large laboratory angle.
Download or read book Measurement of the Two photon Exchange Contribution to Lepton proton Scattering with OLYMPUS written by Lauren Ice and published by . This book was released on 2016 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: The OLYMPUS experiment measured the two-photon exchange contribution to elastic electron-proton scattering, over a range of four-momentum transfer from \(0.6
Download or read book The Contribution of Two photon Exchange in Elastic Lepton proton Scattering written by Colton David Graham O'Connor and published by . This book was released on 2017 with total page 307 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of the electric-to-magnetic ratio of the proton's elastic form factors, GE/GM, have recently been shown to diverge at high momentum transfer, Q2, based on which of two experimental methods is employed. Reanalysis of all results might be able to bring them into agreement if some previously neglected correction were introduced whose magnitude increases with Q2. In the high-energy community, two-photon exchange has become the favored candidate for such a correction. But theoretical models disagree on the size and form of a two-photon exchange correction term entering into elastic lepton-proton scattering and existent empirical data is not sufficiently precise to settle the matter. OLYMPUS is one of several new experiments designed to evaluate R2[gamma], the ratio of the elastic cross sections for positron-proton and electron-proton scattering, whose difference from unity provides a direct measure of the amplitude of the two-photon exchange matrix elements. In this dissertation, OLYMPUS is considered from its motivation, construction, and operation to its analysis, along with the associated Monte Carlo simulation. Special attention is given to the symmetric Møller/Bhabha detector system, which is not described in full elsewhere. The results achieved by the OLYMPUS collaboration, reported herein, achieve unprecedented precision over a wide kinematic range and make a significant contribution to the understanding of two-photon exchange.
Download or read book Two Photon Exchange in Electron proton Scattering written by Gary Kalman Greenhut and published by . This book was released on 1968 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Exclusive Processes at High Momentum Transfer written by A. V. Radyushkin and published by World Scientific. This book was released on 2002 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the physics of exclusive processes at high momentum transfer and their description in terms of generalized parton distributions, perturbative QCD, and relativistic quark models. It covers recent developments in the field, both theoretical and experimental. Contents: Perspectives on Exclusive Processes in QCD (S J Brodsky); High-t Meson Photo- and Electroproduction: A Window on Partonic Structure of Hadrons (J-M Laget); Nucleon Hologram with Exclusive Leptoproduction (A Belitsky & D Muller); QCD Factorization for the Pion Diffractive Dissociation into Two Jets (D Yu Ivanov); GPDs, Form Factors and Compton Scattering (P Kroll); Real Compton Scattering from the Proton (A Nathan); Resonance Exchange Contributions to Wide-Angle Compton Scattering: The D-Term (T Oppermann); Proton-Antiproton Annihilation into Two Photons at Large s (C Weiss); Quark--Hadron Duality Studies at Jefferson Lab; An Overview of New and Exisiting Results (C Keppel); Novel Hard Semiexclusive Processes and Color Singlet Clusters in Hadrons (M Strikman et al.); and other papers. Readership: Theoretical and experimental researchers in nuclear and elementary particle physics.
Download or read book Elastic and Inelastic Electron proton Scattering written by Ernest Albert Allton and published by . This book was released on 1973 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Two photon Exchange Contribution to Elastic Electron proton Scattering Measurements at the VEPP 3 Storage Ring written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Two photon Exchange in Elastic and Inelastic Electron proton Scattering written by W. Melnitchouk and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present an explicit quantum field theoretical calculation of two-photon exchange contribution to elastic electron-proton scattering and to Delta resonance production in electron-proton collisions.
Download or read book Delta Resonance Contribution to Two photon Exchange in Electron proton Scattering written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We calculate the effects on the elastic electron-proton scattering cross section of the two-photon exchange contribution with an intermediate [Delta] resonance. The [Delta] two-photon exchange contribution is found to be smaller in magnitude than the previously evaluated nucleon contribution, with an opposite sign at backward scattering angles. The sum of the nucleon and [Delta] two-photon exchange corrections has the angular dependence compatible with both the polarization transfer and the Rosenbluth methods of measuring the nucleon electromagnetic form factors.
Download or read book Positron proton Scattering written by Andrew Arnold Browman and published by . This book was released on 1964 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: The importance of two-photon exchange in elastic electron-proton scattering was investigated by measuring the ratio of positron-proton to electron-proton scattering. Four momentum transfers as large as 0.756 (BeV/c) to the 2nd power (19.5 F to the -2nd power) were used. The data indicate that two-photon effects are 4.0 = 1.5% larger than those predicted by the radiative corrections at the highest momentum transfers attained in these experiments. The two-photon corrections predicted, using a static charge distribution, fit the data well at lower momentum transfers and forward angles but appear to be small at higher momentum transfers and backward angles. (Author).
Download or read book Two Photon Exchange Effects in Elastic Electron Proton Scattering written by and published by . This book was released on 2013 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two methods, Rosenbluth separation and polarization transfer, can be used to extract the proton form factor ratio [mu]p GEp/GMp, but they do not yield the same results. It is thought that the disagreement is due to two photon exchange corrections to the differential cross sections. High precision proton Rosenbluth extractions were carried out at 102 kinematics points spanning 16 values of momentum transfer Q2, from 0.40 to 5.76 GeV2. Reduced cross sections were found to 1.1% or better for Q2 less than 3 GeV2 increasing to 4% at 5.76 GeV2 The form factor ratios were determined to 1:5-3% for Q2
Download or read book A Measurement of the Two photon Exchange Effect in Elastic Electron proton Scattering with OLYMPUS written by Rebecca Lynn Russell and published by . This book was released on 2016 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: Elastic electron-proton scattering has long been the tool of choice for the study of the proton form factors, GE(Q 2 ) and GM(Q2 ), which describe the electric and magnetic distributions of the proton as a function of momentum transfer. Recent experiments, measuring the form factors from polarization observables in polarized elastic electron-proton scattering, have found values of the ratio GE(Q2 )/GM(Q2) at high Q2 that contradict the results from unpolarized measurements. A proposed explanation for this discrepancy is the unaccounted two-photon exchange radiative correction, which could affect the unpolarized measurements. As this effect is currently not possible to calculate in a model-independent way, the OLYMPUS experiment was designed to make a direct measurement of it by measuring the elastic positron-proton to electron-proton scattering cross section ratio. The experiment was run in 2012 at DESY using the BLAST spectrometer and the DORIS positron and electron beams at 2 GeV incident on a gaseous hydrogen target. To analyze the data, a careful reconstruction of the scattering events, detailed simulation of the experimental setup, and full radiative corrections to the measured cross sections were performed. Preliminary results for the experiment show a statistically significant two-photon exchange effect, increasing over the measurement range of 0.6 GeV2
Download or read book Few body Problems In Physics Proceedings Of The 3rd Asia pacific Conference written by Yupeng Yan and published by World Scientific. This book was released on 2007-01-29 with total page 425 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Asia-Pacific Conferences on Few-Body Problems in Physics tackle cover the various aspects of few-body systems in physics, with high caliber contributions from internationally renowned researchers. Readers will gain a clear picture of the latest developments in the field in both the theoretical and experimental sectors.The scope of these proceedings covers research in the following areas: three-body forces and few-nucleon dynamics, hadron structure and QCD; exotic hadrons and atoms; effective field theory in few-body physics; electromagnetic and weak processes in few-body systems; few-body dynamics in atoms, molecules, Bose-Einstein condensates and quantum dots; few-body approaches to unstable nuclei, nuclear astrophysics and nuclear clustering aspects; and hypernuclear physics.
Download or read book Two Photon Exchange Correction to Parity Violating Elastic Electron Proton Scattering written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Higher-order QED effects play an important role in precision measurements of nucleon elastic form factors in electron scattering. Here we introduce a two-photon exchange QED correction to the parity-violating polarization asymmetry of elastic electron-proton scattering. We calculate this correction in the parton model using the formalism of generalized parton distributions, and demonstrate that it can reach several per cent in certain kinematics, becoming comparable in size with existing experimental measurements of strange-quark effects in the proton neutral weak current.
Download or read book From Parity Violation to Hadronic Structure and more written by Serge Kox and published by Springer Science & Business Media. This book was released on 2007-06-07 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Almost 50 years after the proposal of Lee and Young in 1956 to test the hypothesis of parity violation in weak interactions and the subsequent experimental verification of parity violation by C. S. Wu, parity violation has today become a useful property of weak interactions. This is due to the fact that the focus nowadays has changed: parity violation in weak interactions is no more a topic of investigation but is used as a tool in many different fields ranging from nuclear physics to the search for the hidden extra dimensions requested by string theory. For our first workshop which took place June 5-8, 2002, at the Institut fiir Ke- physik of the Johannes Gutenberg-Universitat Mainz, we concentrated on the in vestigation of the strangeness contribution in the nucleon. This book contains the refereed and selected papers of the second workshop "From Parity Violation to Hadron Structure and more (Part II)", which took place June 8-11, in the Labo- toire de Physique Subatomique et de Cosmologie, in Grenoble. These papers appear in EPJAdirect, the electronic-only part of EPJA, and they are accessible without restrictions. They will also appear in printed form and can be ordered through Springer. The excellent presentations show the dramatic and steady progress in the accuracy of measured parity violating asymmetries over the last few years.
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1976-05 with total page 912 pages. Available in PDF, EPUB and Kindle. Book excerpt:
