论文信息 - Measurement of the Charge-Averaged Elastic Lepton-Proton Scattering Cross Section by the OLYMPUS Experiment. - 字舞流文

Measurement of the Charge-Averaged Elastic Lepton-Proton Scattering Cross Section by the OLYMPUS Experiment.

We report the first measurement of the average of the electron-proton and positron-proton elastic scattering cross sections. This lepton charge-averaged cross section is insensitive to the leading effects of hard two-photon exchange, giving more robust access to the proton's electromagnetic form factors. The cross section was extracted from data taken by the OLYMPUS experiment at DESY, in which alternating stored electron and positron beams were scattered from a windowless gaseous hydrogen target. Elastic scattering events were identified from the coincident detection of the scattered lepton and recoil proton in a large-acceptance toroidal spectrometer. The luminosity was determined from the rates of Møller, Bhabha, and elastic scattering in forward electromagnetic calorimeters. The data provide some selectivity between existing form factor global fits and will provide valuable constraints to future fits.

R. Perrino | R. De Leo | U. Schneekloth | E. Cisbani | D. Lenz | G. Rosner | A. Krivshich | A. Kiselev | F. Maas | P. Lenisa | G. Karyan | M. Statera | V. Carassiti | S. Frullani | G. Ciullo | A. Movsisyan | R. Beck | I. Lehmann | D. Rodríguez Piñeiro | B. Seitz | S. Belostotski | A. Izotov | O. Miklukho | Y. Naryshkin | D. Veretennikov | Y. Holler | L. Ice | D. Hasell | A. Schmidt | Y. Ma | P. Eversheim | R. Redwine | M. Contalbrigo | A. Thiel | J. Hauschildt | V. Yeganov | N. Görrissen | P. Hoffmeister | J. Bernauer | M. Kohl | J. Bessuille | J. Diefenbach | K. Dow | J. Kelsey | M. Murray | T. W. Donnelly | N. Akopov | G. Elbakian | G. Gavrilov | R. Kaiser | H. Marukyan | J. Calarco | R. Russell | A. Winnebeck | D. Khaneft | B. Henderson | R. Milner | R. Alarcon | S. Lumsden | B. Gläser | C. Funke | O. Ates | H. Vardanyan | E. Ihloff | C. Vidal | F. Brinker | A. Avetisyan | P. Klassen | C. O'Connor | R. Pérez Benito

[1] G. A. Miller,et al. Defining the proton radius: A unified treatment , 2018, Physical Review C.

[2] J. Arrington,et al. Proton and Neutron Electromagnetic Form Factors and Uncertainties , 2017, 1707.09063.

[3] B. Raue,et al. Two-photon exchange in elastic electron–proton scattering , 2017, 1703.03874.

[4] D. Hasell. Hard two-photon contribution to elastic lepton-proton scattering determined by the OLYMPUS experiment , 2016, Physical review letters.

[5] U. Schneekloth,et al. Measurement and tricubic interpolation of the magnetic field for the OLYMPUS experiment , 2016, 1603.06510.

[6] F. Maas,et al. Design and performance of a lead fluoride detector as a luminosity monitor , 2016, 1602.01702.

[7] P. Lenisa,et al. The OLYMPUS internal hydrogen target , 2014, 1404.0579.

[8] W. Meyer,et al. Well-established nucleon resonances revisited by double-polarization measurements. , 2012, Physical review letters.

[9] R. Perrino,et al. The OLYMPUS experiment , 2012, 1312.1730.

[10] S. Escoffier,et al. Final analysis of proton form factor ratio data at Q(2)=4.0, 4.8, and 5.6 GeV2 , 2011, 1102.5737.

[11] D. Bosnar,et al. High-precision determination of the electric and magnetic form factors of the proton , 2010, 1108.3533.

[12] Nuruzzaman,et al. Recoil polarization measurements of the proton electromagnetic form factor ratio to Q2 = 8.5 GeV2. , 2010, Physical review letters.

[13] H. Kolster,et al. The BLAST experiment , 2009 .

[14] W. Melnitchouk,et al. Global analysis of proton elastic form factor data with two-photon exchange corrections , 2007, 0707.1861.

[15] E. Tomasi-Gustafsson,et al. Structure function method applied to polarized and unpolarized electron-proton scattering: A solution of the G E ( p ) / G M ( p ) discrepancy , 2006, hep-ph/0603132.

[16] E. Tomasi-Gustafsson,et al. Charge asymmetry for electron (positron)-proton elastic scattering , 2006, hep-ph/0612177.

[17] Y. Sato,et al. The ratio of proton electromagnetic form factors via recoil polarimetry at Q2=1.13(GeV/c)2 , 2006 .

[18] W. Melnitchouk,et al. Two-photon exchange in elastic electron-nucleon scattering , 2005, nucl-th/0506039.

[19] S. Brodsky,et al. The two-photon exchange contribution to elastic electron-nucleon scattering at large momentum transfer , 2005, hep-ph/0502013.

[20] E. al.,et al. Proton elastic form factor rations to Q = 3.5 GeV 2 by polarization transfer , 2005, nucl-ex/0501018.

[21] O. Baker,et al. Precision Rosenbluth measurement of the proton elastic form factors. , 2004, Physical review letters.

[22] J. J. Kelly. Simple parametrization of nucleon form factors , 2004 .

[23] S. Brodsky,et al. Partonic calculation of the two-photon exchange contribution to elastic electron-proton scattering at large momentum transfer. , 2004, Physical review letters.

[24] M. Christy,et al. Measurements of Electron Proton Elastic Cross Sections for 0.4 , 2004, nucl-ex/0401030.

[25] J. Arrington. Implications of the discrepancy between proton form-factor measurements , 2003, nucl-ex/0309011.

[26] M. Vanderhaeghen,et al. How to reconcile the Rosenbluth and the polarization transfer methods in the measurement of the proton form factors. , 2003, Physical review letters.

[27] W. Melnitchouk,et al. Two-photon exchange and elastic electron-proton scattering. , 2003, Physical review letters.

[28] L. Maximon,et al. Radiative corrections to electron-proton scattering , 2000, nucl-th/0002058.

[29] Lang,et al. Measurements of the proton elastic form factors for 1 <= Q2 <= 3 (GeV/c)2 at SLAC. , 1994, Physical review. D, Particles and fields.

[30] Griffioen,et al. Measurements of the electric and magnetic form factors of the proton from Q2=1.75 to 8.83 (GeV/c)2. , 1992, Physical review letters.

[31] Jean-Arcady Meyer,et al. Measurement of proton and neutron electromagnetic form factors at squared four-momentum transfers up to 3 (GeV/c)2 , 1973 .

[32] Richard E. Taylor,et al. Measurement of the ratio of the proton form factors, GE/GM, at high momentum transfers and the question of scaling , 1970 .

[33] L. Mo,et al. Radiative Corrections to Elastic and Inelastic e p and mu p Scattering , 1969 .