Download or read book Parity Violation in Forward Angle Elastic Electron proton Scattering written by Grady Wilson Miller and published by . This book was released on 2001 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Parity Violation in Forward Angle Elastic Electron Proton Scattering written by and published by . This book was released on 1999 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: HAPPEX is a new experiment to probe the strange structure of the nucleon with parity violating electron scattering. We describe the physics motivation, provide an experimental overview and report on the results from the first data run. The asymmetry for the elastic scattering of 3.3 GeV electrons off target protons at a scattering angle of 12.5 degrees was measured to a precision of 15% of itself. The contribution from strange quark form factors was found to be zero within the experimental and theoretical uncertainties.
Download or read book Parity Violation in Elastic Electron Scattering written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of Experiment E04-115 (the G0 backward angle measurement) at Jefferson Lab is to investigate the contributions of strange quarks to the fundamental properties of the nucleon. The experiment measures parity-violating asymmetries in elastic electron scattering off hydrogen and quasielastic electron scattering off deuterium at backward angles at Q2 = 0.631 (GeV/c)2 and Q2 = 0.232 (GeV/c)2. The backward angle measurement represents the second phase of the G0 experiment. The first phase, Experiment E00-006 (the G0 forward angle experiment), measured parity-violating asymmetries in elastic electron scattering off hydrogen at forward angles over a Q2 range of 0.1-1.0 (GeV/c)2. The experiments used a polarized electron beam and unpolarized hydrogen and deuterium liquid targets. From these measurements, along with the electromagnetic form factors, one can extract the contribution of the strange quark to the proton's charge and magnetization distributions. This thesis represents a fi.
Download or read book A 3 Measurement of the Beam Normal Single Spin Asymmetry in Forward Angle Elastic Electron Proton Scattering Using the Qweak Setup written by and published by . This book was released on 2013 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt: The beam normal single spin asymmetry generated in the scattering of transversely polarized electrons from unpolarized nucleons is an observable of the imaginary part of the two-photon exchange process. Moreover, it is a potential source of false asymmetry in parity violating electron scattering experiments. The Q{sub weak} experiment uses parity violating electron scattering to make a direct measurement of the weak charge of the proton. The targeted 4% measurement of the weak charge of the proton probes for parity violating new physics beyond the Standard Model. The beam normal single spin asymmetry at Q{sub weak} kinematics is at least three orders of magnitude larger than 5 ppb precision of the parity violating asymmetry. To better understand this parity conserving background, the Q{sub weak} Collaboration has performed elastic scattering measurements with fully transversely polarized electron beam on the proton and aluminum. This dissertation presents the analysis of the 3% measurement (1.3% statistical and 2.6% systematic) of beam normal single spin asymmetry in electronproton scattering at a Q2 of 0.025 (GeV/c)2. It is the most precise existing measurement of beam normal single spin asymmetry available at the time. A measurement of this precision helps to improve the theoretical models on beam normal single spin asymmetry and thereby our understanding of the doubly virtual Compton scattering process.
Download or read book New Measurement of Parity Violation in Elastic Electron Proton Scattering and Implications for Strange Form Factors written by and published by . This book was released on 2001 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from the proton. The result is A = -15.05 +- 0.98(stat) ± 0.56(syst) ppm at the kinematic point theta{sub lab} = 12.3 degrees and Q2 = 0.477 (GeV/c)2. The measurement implies that the value for the strange form factor (G{sub E}{sup s} + 0.392 G{sub M}{sup s})/(G{sub M}{sup p} [mu]{sub p}) = 0.069 +- 0.056 +- 0.039, where the first error is experimental and the second arises from the uncertainties in electromagnetic form factors. This measurement is the first fixed-target parity violation experiment that used either a ''strained'' GaAs photocathode to produce highly polarized electrons or a Compton polarimeter to continuously monitor the electron beam polarization.
Download or read book Parity Violation In Electron Scattering Proceedings Of The Workshop written by E J Beise and published by World Scientific. This book was released on 1990-08-23 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: These proceedings cover the recent progress and future directions of parity violation in electron scattering. Both experimental and theoretical issues are discussed, such as those of hadronic structure, radiative corrections, and tests of the standard model. There are three sessions, the first of which serves as a general overview of theory and experiment. The second session deals with the technical aspects of making a measurement of the parity violating asymmetry in electron scattering, including not only detector design but polarized electron beams and beam polarimeters.. The remaining session covers the corrections to lowest order parity violating cross sections.
Download or read book Beam Normal Single Spin Asymmetry in Forward Angle Inelastic Electron Proton Scattering Using the Q Weak Apparatus written by and published by . This book was released on 2014 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Q-weak experiment in Hall-C at the Thomas Jefferson National Accelerator Facility has made the first direct measurement of the weak charge of the proton through the precision measurement of the parity-violating asymmetry in elastic electron-proton scattering at low momentum transfer. There is also a parity conserving Beam Normal Single Spin Asymmetry or transverse asymmetry (B_n) on H_2 with a sin(phi)-like dependence due to two-photon exchange. If the size of elastic B_n is a few ppm, then a few percent residual transverse polarization in the beam, combined with small broken azimuthal symmetries in the detector, would require a few ppb correction to the Q-weak data. As part of a program of B_n background studies, we made the first measurement of B_n in the N-to-Delta(1232) transition using the Q-weak apparatus. The final transverse asymmetry, corrected for backgrounds and beam polarization, was found to be B_n = 42.82 ± 2.45 (stat) ± 16.07 (sys) ppm at beam energy E_beam = 1.155 GeV, scattering angle theta = 8.3 deg, and missing mass W = 1.2 GeV. B_n from electron-nucleon scattering is a unique tool to study the gamma*̂ Delta Delta form factors, and this measurement will help to improve the theoretical models on beam normal single spin asymmetry and thereby our understanding of the doubly virtual Compton scattering process. To help correct false asymmetries from beam noise, a beam modulation system was implemented to induce small position, angle, and energy changes at the target to characterize detector response to the beam jitter. Two air-core dipoles separated by 1̃0 m were pulsed at a time to produce position and angle changes at the target, for virtually any tune of the beamline. The beam energy was modulated using an SRF cavity. The hardware and associated control instrumentation will be described in this dissertation. Preliminary detector sensitivities were extracted which helped to reduce the width of the measured asymmetry. The beam modulation system has also proven valuable for tracking changes in the beamline optics, such as dispersion at the target.
Download or read book Parity Violation in Elastic Electron Proton Scattering written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Measuring the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from protons is a practical technique for determining the contribution of strange quarks to the charge radius and magnetic moment of the nucleon. First results have recently been published by JLab and MIT-Bates.
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 From Parity Violation to Hadronic Structure and more written by K. de Jager and published by Springer Science & Business Media. This book was released on 2008-06-21 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the proceedings of the third international workshop on From Parity Violation to Hadronic Structure and More. The many applications of parity violation are way beyond the scope of what Lee and Yang could have imagined fifty years after their proposal. For the physics topics discussed during this workshop, the application of parity violation has become a standard work horse allowing for the extraction of many physics topics in different experiments.
Download or read book Parity Violation In Atoms And In Polarized Electron Scattering written by Marie-anne Bouchiat and published by World Scientific. This book was released on 1999-07-13 with total page 550 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the last few years there has been considerable progress in improving the accuracy of parity violation experiments in electron scattering at high energy and in atomic physics. Recent results are a challenge to the standard electroweak theory and our understanding of hadron structure. This book is an extensive review of the advances in this field. The theoretical framework is presented at a pedagogical level, experiments and future projects are reviewed, and the results and their interpretation are discussed in depth.
Download or read book Parity Violation in Electron Scattering written by E. J. Beise and published by World Scientific Publishing Company. This book was released on 1990 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: These proceedings cover the recent progress and future directions of parity violation in electron scattering. Both experimental and theoretical issues are discussed, such as those of hadronic structure, radiative corrections, and tests of the standard model. There are three sessions, the first of which serves as a general overview of theory and experiment. The second session deals with the technical aspects of making a measurement of the parity violating asymmetry in electron scattering, including not only detector design but polarized electron beams and beam polarimeters.. The remaining session covers the corrections to lowest order parity violating cross sections.
Download or read book Measurement of the Strange Quark Contribution to Proton Structure Through Parity Violating Electron Proton Scattering written by Kazutaka Nakahara and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The G0 (G-Zero) forward angle experiment completed in Hall C of the Thomas Jefferson National Accelerator Facility (TJNAF) has measured the parity violating asymmetries in elastic electron-proton scattering over a Q2 range of 0.12
Download or read book Weak Charge of the Proton written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: I review the role of two-boson exchange corrections to parity-violating elastic electron-proton scattering. Direct calculations of contributions from nucleon and Delta intermediate states show generally small, [script O](1-2%), effects over the range of kinematics relevant for proton strangeness form factor measurements. For the forward angle Qweak experiment at Jefferson Lab, which aims to measure the weak charge of the proton, corrections from the gammaZ box diagram are computed within a dispersive approach and found to be sizable at the E~1 GeV energy scale of the experiment.
Download or read book Elastic Electron proton Scattering at Forward Angles written by Gerald Russell Rouse and published by . This book was released on 1965 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Determination of the Proton s Weak Charge Via Parity Violating Electron Scattering written by and published by . This book was released on 2015 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Qweak experiment, which completed running in May of 2012 at Jefferson Laboratory, has measured the parity-violating asymmetry in elastic electron-proton scattering at four-momentum transfer Q2=0.025 (GeV/c)2 in order to provide the first direct measurement of the proton's weak charge, Qpw. The Standard Model makes firm predictions for the weak charge; deviations from the predicted value would provide strong evidence of new physics beyond the Standard Model. Using an 89% polarized electron beam at 145 microA scattering from a 34.4 cm long liquid hydrogen target, scattered electrons were detected using an array of eight fused-silica detectors placed symmetric about the beam axis. The parity-violating asymmetry was then measured by reversing the helicity of the incoming electrons and measuring the normalized difference in rate seen in the detectors. The low Q2 enables a theoretically clean measurement; the higher order hadronic corrections are constrained using previous parity-violating electron scattering world data. The experimental method will be discussed, with recent results constituting 4% of our total data and projections of our proposed uncertainties on the full data set.
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.
