Download or read book Parity violating Electroweak Asymmetry in rvec E P Scattering written by and published by . This book was released on 2004 with total page 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 protons. Significant contributions to this asymmetry could arise from the contributions of strange form factors in the nucleon. The measured asymmetry is A = -15.05 ± 0.98(stat) ± 0.56(syst) ppm at the kinematic point [theta]{sub lab} = 12.3{sup o} and Q2 = 0.477 (GeV/c)2. Based on these data as well as data on electromagnetic form factors, we extract the linear combination of strange form factors G{sub E}{sup s} + 0.392G{sub M}{sup s} = 0.014 ± 0.020 ± 0.010 where the first error arises from this experiment and the second arises from the electromagnetic form factor data. This paper provides a full description of the special experimental techniques employed for precisely measuring the small asymmetry, including the first use of a strained GaAs crystal and a laser-Compton polarimeter in a fixed target parity-violation experiment.

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 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 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 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 Parity Violation in Forward Angle Elastic Electron Proton Scattering written by and published by . This book was released on 2001 with total page 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 at Jefferson Laboratory. The kinematic point ([theta]_lab = 12.3 deg. and (Q^2) = 0.48 (GeV/c)^2) is chosen to provide sensitivity to the strange electric form factor G^s_E. A 3.36 GeV beam of longitudinally polarized electrons was scattered from protons in a liquid hydrogen target. The scattered flux was detected by a pair of spectrometers which focussed the elastically-scattered electrons onto total-absorption detectors. The detector signals were integrated and digitized by a custom data acquisition system. A feedback system reduced systematic errors by controlling helicity-correlated beam intensity differences at the sub-ppm (part per million) level. The experimental result, A = 14.5 +/- 2.0 (stat) +/- 1.1 (syst) ppm, is consistent with the electroweak Standard Model with no additional contributions from strange quarks. In particular, the measurement implies G^S_E + 0.39 G^s_M = 0.023 +/- 0.040 +/- 0.026 ([delta]G^n_E), where the last uncertainty is due to the estimated uncertainty in the neutron electric form factor G^n_E . This result represents the first experimental constraint of the strange electric form factor.

Download or read book Parity Violating Electron Scattering from 4He and the Strange Electric Form Factor of the Nucleon written by and published by . This book was released on 2005 with total page 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 4He at an average scattering angle [theta]{sub lab} = 5.7 degrees and a four-momentum transfer Q2 = 0.091 GeV2. From these data, for the first time, the strange electric form factor of the nucleon G{sub E}{sup s} can be isolated. The measured asymmetry of A{sub PV} = 6.72 ± 0.84 (stat) ± 0.21 (syst) parts per million yields a value of G{sub E}{sup s} = -0.038 ± 0.042 (stat) ± 0.010 (syst), consistent with zero.

Download or read book Measurement of Parity violating Asymmetry in Electron deuteron Inelastic Scattering written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The parity-violating asymmetries between a longitudinally-polarized electron beam and an unpolarized deuterium target have been measured recently. The measurement covered two kinematic points in the deep inelastic scattering region and five in the nucleon resonance region. We provide here details of the experimental setup, data analysis, and results on all asymmetry measurements including parity-violating electron asymmetries and those of inclusive pion production and beam-normal asymmetries. The parity-violating deep-inelastic asymmetries were used to extract the electron-quark weak effective couplings, and the resonance asymmetries provided the first evidence for quark-hadron duality in electroweak observables. These electron asymmetries and their interpretation were published earlier, but are presented here in more detail.

Download or read book Towards a Precision Measurement of Parity violating E p Elastic Scattering at Low Momentum Transfer written by Jie Pan and published by . This book was released on 2012 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electroweak -- Standard Model -- Weak Charge -- Weak Mixing Angle -- Track Reconstruction -- Momentum Transfer -- e-p Scattering -- Parity Violation -- Scanner Detector -- Flux Profile Image -- Parity Violating Asymmetry -- Cerenkov.

Download or read book Parity Violating Electron Deuteron Scattering and the Proton s Neutral Weak Axial Vector Form Factor written by and published by . This book was released on 2004 with total page 102003 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report on a new measurement of the parity-violating asymmetry in quasielastic electron scattering from the deuteron at backward angles at Q2 = 0.038 (GeV/c)2. This quantity provides a determination of the neutral weak axial vector form factor of the nucleon, which can potentially receive large electroweak corrections. The measured asymmetry A = z3.51±0.57 (stat)±0.58 (syst) ppm is consistent with theoretical predictions. We also report on updated results of the previous experiment at Q2 = 0.091 (GeV/c)2, which are also consistent with theoretical predictions.

Download or read book Parity violation in Elastic Electron Scattering A First Measurement of the Parity violating Asymmetry at Q2 written by Stephanie L. Bailey and published by . This book was released on 2007 with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis represents a first measurement of a parity-violating asymmetry in elastic electron scattering at Q2 = 0.631 (GeV/c) 2 off hydrogen at backward angles. This work is based on data obtained during the first part of the run, beginning in March 2006 and ending in May 2006. During this period, a total of 15 C of beam charge was accumulated. The total accumulated charge represents about 15% of the 110 C which was proposed for this Q2. The measured asymmetry is A = (-47.4 +/- 7.1 +/- 5.9 +/- 11.8) ppm, where the first uncertainty is due to statistics, the second uncertainty is systematic, and the third uncertainty is associated with the blinding factor. This result is consistent with a zero contribution from the strange quarks. The helicity-correlated beam properties and slopes are under adequate control for the final precision of the experiment.

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 Parity Violation at 8 12 GeV at Jlab written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Experiments on parity violation in electron scattering measure the asymmetry A = [sigma][sub R] - [sigma][sub L]/[sigma][sub R] + [sigma][sub L] where [sigma][sub R(L)] is the cross section for Right(Left) handed longitudinally polarized electrons. This asymmetry arises, in first order, from the interference between photon and Z-boson exchange amplitudes. Experiments make two basic uses of the Z-boson as a probe in electron-quark or electron-nucleon scattering. Historically the first usage was to test the electroweak theory in regions of kinematics where the hadronic structure is sufficiently understood. They discuss the application of higher energies at Jefferson Lab to repeat the SLAC e-D deep inelastic parity violation experiment [1] at a level of precision [approx] 0.5% in sin[sup 2][theta][sub W] which would be a useful constrain on extensions of the Standard Model [2]. The second, more recent usage of the Z-boson probe is to assume the Standard Model is correct at about the 1% level and use this as a unique method to address fundamental issues of nucleon structure, such as: (1) are the strange quarks an important component of the nucleon [3]; (2) In deep inelastic scattering, are the high momentum quarks u or d quarks? To address the first question, they discuss the feasibility of extending the HAPPEX experiment to higher Q[sup 2]. For the second question, they discuss a possible measurement of the ratio of valence quarks d/u in the proton using deep inelastic parity violation.

Download or read book Measurement of the Parity Violating Asymmetries in Electron Deuteron Scattering in the Nucleon Resonance Region written by and published by . This book was released on 2013 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report on parity-violating asymmetries in the nucleon resonance region measured using 5 - 6 GeV longitudinally polarized electrons scattering off an unpolarized deuterium target. These results are the first parity-violating asymmetry data in the resonance region beyond the [Delta](1232), and provide a verification of quark-hadron duality in the nucleon electroweak [gamma] Z interference structure functions at the (10-15)% level. The results are of particular interest to models relevant for calculating the [gamma] Z box-diagram corrections to elastic parity-violating electron scattering measurements.

Download or read book Testing the Standard Model written by Christophe Match and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamental interactions between electrons and protons, coupling between photons and Z bosons, and the underlying substructure of the proton, can all be probed through scattering experiments designed to measure the parity-violating asymmetry due to a mixing of electromagnetic and weak forces. Our research involves testing the limits of the standard model in search of new physics, by comparing high precision theoretical predictions of this asymmetry, along with the proton's weak charge and the weak mixing angle, to recent experimental measurements. We were ultimately able to achieve results consistent with experimental observations, by accounting for radiative corrections beyond single boson exchange. Our calculations include up to first-order Feynman diagrams containing 1 loop integrals, soft-photon bremsstrahlung, and we account for additional box diagram corrections. We also consider the addition of a new weakly-interacting dark Z boson (Z') to the Standard Model, and investigate how it affects the calculated asymmetry.

Download or read book Parity Violating Asymmetries and Weak Neutral Currents written by Thomas Tsao and published by . This book was released on 1980 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: