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 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 Measurement of the Polarization in Elastic Electron ProtonScattering written by and published by . This book was released on 1970 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We have measured the (illegible) scattering (?-illegible) of electrons (?-illegible) from a polarized proton target. (illegible) between (?-illegible) imaginary part of the two-photon-(illegible) (illegible) photon-exchange amplitude could produce (?-illegible) (illegible) results indicate no asymmetry within (illegible) 1 to 2% at four(?-illegible)-momentum transfer (illegible) (illegible) 0.98 (GeV/c)2.

Download or read book Measurement of the Polarization Parameter A 00nn for Elastic Proton proton Scattering Between 400 and 600 MeV written by Didier Besset and published by . This book was released on 1978 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurements of the Polarisation of the Recoil Proton in Elastic Electron Proton Scattering at 92 written by H. C. Kirkman and published by . This book was released on 1970 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of the polarization parameter A for elastic proton proton scattering between 400 and 600 MeV written by Didier Besset and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurements of the Polarisation of the Recoil Proton in Elastic Electron Proton Scattering at Q2 written by H. C. Kirkman and published by . This book was released on 1970 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Polarization Measurements for Proton Elastic Scattering from 88Sr 89Y 92Zr 92 94Mo and 118 120Sn Near Isobaric Analog Resonances written by Jerry Lynn Ellis and published by . This book was released on 1970 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of proton Proton Elastic Scattering at 197 4 MeV with Longitudinally Polarized Beam and Target written by Bernd Lorentz and published by . This book was released on 1998 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of the Polarization Parameter Aoonn for Elastic Proton proton Scattering Between 400 and 600 MeV written by Didier Besset and published by . This book was released on 1978 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Precision Measurement of the E p e p Elastic Scattering Cross Section Ratio at the OLYMPUS Experiment written by Brian Scott Henderson and published by . This book was released on 2016 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of the ratio of the proton elastic form factors ([mu]pGe/Gm) using Rosenbluth separation and those using polarization-based techniques show a strong discrepancy, which has persisted both in modern experimental results and in re-analyses of previous data. The most widely accepted hypothesis to explain this discrepancy is the treatment of the contributions from hard two-photon exchange (TPE) to elastic electron-proton scattering in the radiative corrections applied to the Rosenbluth separation measurements. Calculations of the hard TPE contribution are highly model dependent, but the effect may be measured experimentally with a precise determination of the ratio of the positron-proton and electron-proton elastic scattering cross sections. The OLYMPUS experiment collected approximately 4 fb-1 of e+p and e-p scattering data at the DORIS storage ring at DESY in 2012, with the goal of measuring the elastic [sigma]e+p/[sigma]e-p ratio over the kinematic range (0.4

Download or read book A Measurement of the Cross Section and Polarization in Proton deuteron Elastic Scattering at 198 MeV written by Rexford Earle Adelberger and published by . This book was released on 1968 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of the Polarization Parameter in Small Angle Proton proton Elastic Scattering at 6 GeV c written by and published by . This book was released on 1975 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurements of the Proton Electromagnetic Form Factor Ratio From Elastic E P E P Scattering at Momentum Transfer Q2 written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Among the fundamental observables of nucleon structure, electromagnetic form factors are a crucial benchmark for modern calculations describing the strong interaction dynamics of the nucleon's quark constituents. Electromagnetic probes are traditionally preferered to the hadronic beams. The electromagnetic interaction is a powerful tool for investigating the nucleon structure since it is well understood and it reveals observables that can be directly interpreted in terms of the current carried by the quarks. Elastic scattering leads to the form factors that describe the spatial charge and current distributions inside the nucleon. The reaction mechanism is assumed to be one photon exchange, the electromagnetic interaction is exactly calculable in QED, and one can safely extract the information on the hadronic vertex. The most important feature of early measurements of proton form factor ratio GEp/GMp with recoil polarization technique at Q2 up to 5.6 (GeV/c)2 is the sharp decline of the ratio with Q2 increases, indicating that GEp falls much faster than GMp. This contradicts to data obtained by Rosenbluth separation method. An intriguing question was whether GEp will continue to decrease or become constant when Q2 increases. New set of measurements of proton form factor ratio GEp/GMp at Q2 = 2.5, 5.2, 6.7 and 8.5 (GeV/c)2 have been conducted at JLab Hall C using ~85% longitudinally polarized electron elastic scattering from unpolarized hydrogen target. Recoil protons were detected in the HMS magnetic spectrometer with the standard detector package, combined with newly installed trigger scintillators and Focal Plane Polarimeter. The BigCal electromagnetic calorimeter (1744 channel) have been used for electron detection. Data obtained in this experiment show that GEp/GMp ratio continued to drop with Q2 and may cross 'zero' at Q2> 10-15 (GeV/c)2. Intensive theoretical and experimental efforts over the past decade have aimed at explaining the discrepancy between data for the proton form factor ratio GEp/GMp obtained from cross section and polarization measurements. It was assumed that the two photon exchange contribution might be responsible for difference of GEp/GMp ratio obtained by Rosenbluth separation method and recoil polarization technique. The kinematical dependence of polarization transfer observables in elastic electron-proton scattering at Q2 = 2.5 (GeV/c)2 have been used in search of effects of 2[gamma] contribution. For a wide range of values of the virtual photon polarization [Sigma] ([Sigma] = 0.15, 0.63, and 0.77), the proton form factor ratio and longitudinal polarization transfer component were measured with statistical uncertainties of ±0.01 and ±0.005, respectively. Our data provide significant constraints on models of nucleon structure.

Download or read book Measurements of the Polarization in Proton proton Elastic Scattering from 2 5 to 5 15 GeV c written by James H. Parry and published by . This book was released on 1971 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Measurement of the Polarization Parameter in Neutron proton Charge Exchange Scattering from 2 12 GeV c written by Randal Charles Ruchti and published by . This book was released on 1973 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Elastic K proton Scattering at 910 MeV c written by Warner Hirsch and published by . This book was released on 1963 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: