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 Measurement of the Parity Violating Asymmetry in Deep Inelastic Scattering at JLab 6 GeV written by and published by . This book was released on 2013 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: The parity-violating asymmetry in deep inelastic scattering (PVDIS) offers us a useful tool to study the weak neutral couplings and the hadronic structure of the nucleon, and provides high precision tests on the Standard Model. During the 6 GeV PVDIS experiment at the Thomas Jefferson National Accelerator Facility, the parity-violating asymmetries A{sub PV} of a polarized electron beam scattering off an unpolarized deuteron target in the deep inelastic scattering region were precisely measured at two Q2 values of 1.1 and 1.9 (GeV/c)2. The asymmetry at Q2=1.9 (GeV/c)2 can be used to extract the weak coupling combination 2C2u - C2d, assuming the higher twist effect is small. The extracted result from this measurement is in good agreement with the Standard Model prediction, and improves the precision by a factor of five over previous data. In addition, combining the asymmetries at both Q2 values provides us extra knowledge on the higher twist effects. The parity violation asymmetries in the resonance region were also measured during this experiment. These results are the first APV data in the resonance region beyond the [Delta] (1232). They provide evidence that the quark hadron duality works for APV at the (10-15)% level, and set constraints on nucleon resonance models that are commonly used for background calculations to other parity-violating electron scattering measurements.

Download or read book Parity Violating Deep Inelastic Electron Scattering from the Deuteron at 6 GeV written by and published by . This book was released on 2013 with total page 79 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experiment that measured the parity violating (PV) asymmetry Ad in e-2H deep inelastic scattering (DIS) at Q2 ~ 1.10 and 1.90 (GeV/c)2 and xB ~ 0.3 was completed in experimental Hall A at the Thomas Jefferson National Accelerator Facility. The asymmetry can be used to extract the neutral weak coupling combination (2C2u-C2d), providing a factor of five to six improvement over the current world data. To achieve this precision, asymmetries of the 10-4 level needed to be measured at event rates up to 500 kHz with high electron detection efficiency and high pion background rejection capability. A specialized scaler-based counting data acquisition system (DAQ) with hardware-based particle identification was successfully implemented. The statistical quality of the asymmetry measurement agreed with the Gaussian distribution to over five orders of magnitudes and the experimental goal of 3-4% statistical uncertainty was achieved. The design and performance of the new DAQ system is presented with the preliminary asymmetry results given in the end.

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 Measurement of the Parity violating Asymmetry in Inclusive Electroproduction of pi Near the Delta0 Resonance written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The parity-violating (PV) asymmetry of inclusive [pi]- production in electron scattering from a liquid deuterium target was measured at backward angles. The measurement was conducted as a part of the G0 experiment, at a beam energy of 360 MeV. The physics process dominating pion production for these kinematics is quasi-free photoproduction off the neutron via the [Delta]0 resonance. In the context of heavy-baryon chiral perturbation theory (HB[chi]PT), this asymmetry is related to a low energy constant d[Delta]- that characterizes the parity-violating [gamma]N[Delta] coupling. Zhu et al. calculated d[Delta]- in a model benchmarked by the large asymmetries seen in hyperon weak radiative decays, and predicted potentially large asymmetries for this process, ranging from A[gamma]- = -5.2 to +5.2 ppm. The measurement performed in this work leads to A[gamma]- = -0.36 " 1.06 " 0.37 " 0.03 ppm (where sources of statistical, systematic and theoretical uncertainties are included), which would disfavor enchancements considered by Zhu et al. proportional to Vud/Vus. The measurement is part of a program of inelastic scattering measurements that were conducted by the G0 experiment, seeking to determine the N-[Delta] axial transition form-factors using PV electron scattering.

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 Inelastic Scattering Experiments at 6 GeV and 12 GeV Jefferson Lab written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We report on the measurement of parity-violating asymmetries in the deep inelastic scattering and nucleon resonance regions using inclusive scattering of longitudinally polarized electrons from an unpolarized deuterium target. The effective weak couplings C$_{2q}$ are accessible through the deep-inelastic scattering measurements. Here we report a measurement of the parity-violating asymmetry, which yields a determination of 2C$_{2u}$ - C$_{2d}$ with an improved precision of a factor of five relative to the previous result. This result indicates evidence with 95% confidence that the 2C$_{2u}$ - C$_{2d}$ is non-zero. This experiment also provides the first parity-violation data covering the whole resonance region, which provide constraints on nucleon resonance models. Finally, the program to extend these measurements at Jefferson Lab in the 12 GeV era using the Solenoidal Large Intensity Device was also discussed.

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 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 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:

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 Further Tests of Parity Violation in Inelastic Electron Scattering 16 2 to 22 2 GeV Y written by and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Further measurements of parity-violating asymmetries in inelastic scattering of polarized electrons from deuterium were made for a range of y values from 0.15 to 0.36. Only a small y-dependemce was observed in the asymmetries. Using the quark-parton model, these results are in good agreement with the Weinberg-Salam predictions. A value of the parameter sin2theta/sub W/ = 0.224 +- 0.020 was obtained. 4 figures.

Download or read book Measurement of the Parity Violating Asymmetry in Elastic Electron Scattering Off 208Pb written by and published by . This book was released on 2014 with total page 197 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Lead Radius Experiment (PREX) was carried out in order to provide a model-independent measurement of the RMS radius sqrt(r-2/n) of the neutron distribution in the 208Pb nucleus. The parity-violating scattering asymmetry for longitudinally polarized 1.06 GeV electrons from an unpolarized 208Pb target was measured at Q2 = 0.00880 GeV2. This measurement was performed by the PREX collaboration in Hall A at Jefferson Laboratory in Newport News, VA, between March and June, 2010. The electron detectors used in this measurement were designed and fabricated by University of Massachusetts-Amherst and Smith College. The resulting parity-violating asymmetry was measured as APV = 656±60(stat.)±14(sys.) ppb. This asymmetry extrapolates to a difference in radii between the nuclear neutron and proton distributions of sqrt(r-2/n)-sqrt(r-2/p)=0.33^+0.16/-0.18 fm.

Download or read book Measurement of the Parity Violating Asymmetry in Elastic Electron Scattering Off 208Pb written by Jonathan William Wexler and published by . This book was released on 2014 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Lead Radius Experiment (PREX) was carried out in order to provide a model independent measurement of the RMS radius square root r2 of the neutron distribution in the 208Pb nucleus. The parity-violating scattering asymmetry for longitudinally polarized 1.06 GeV electrons from an unpolarized 208Pb target was measured at Q2 = 0.00880 GeV2. This measurement was performed by the PREX collaboration in Hall A at Jefferson Laboratory in Newport News, VA, between March and June, 2010. The electron detectors used in this measurement were designed and fabricated by University of Massachusetts-Amherst and Smith College. The resulting parity-violating asymmetry was measured as APV = 656±60(stat.)±14(sys.) ppb. This asymmetry extrapolates to a difference in radii between the nuclear neutron and proton distributions of square root r2n - square root r2p =0.33 +0.16 -0.18 fm.

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 The G0 Experiment written by Philip G. Roos and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The G0 experiment will measure the parity-violating asymmetries in elastic electron-nucleon scattering. The experiment is being performed in Hall C at the Jefferson Laboratory using a polarized electron beam and a dedicated experimental setup. Measurements of the electron-proton asymmetries will be made at both forward and backward angles, and electron-deuteron asymmetries at the backward angles. These measurements will cover a momentum transfer range of 0.1 - 1.0 GeV2/c2. From these data the vector neutral weak form factors, GEZ and GMZ, and the effective axial current of the nucleon, GAe, may be extracted. When combined with the known electromagnetic form factors, one will be able to extract the contributions of u, d, and s quarks to the protons charge and magnetization distributions. The first measurements at forward angles for the full momentum transfer range have very recently been successfully completed and preliminary results are presented here.

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.