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Christy ME, Gautam T, Ou L, Schmookler B, Wang Y, Adikaram D, Ahmed Z, Albataineh H, Ali SF, Aljawrneh B, Allada K, Allison SL, Alsalmi S, Androic D, Aniol K, Annand J, Arrington J, Atac H, Averett T, Ayerbe Gayoso C, Bai X, Bane J, Barcus S, Bartlett K, Bellini V, Beminiwattha R, Bericic J, Bhatt H, Bhetuwal D, Biswas D, Brash E, Bulumulla D, Camacho CM, Campbell J, Camsonne A, Carmignotto M, Castellanos J, Chen C, Chen JP, Chetry T, Cisbani E, Clary B, Cohen E, Compton N, Cornejo JC, Covrig Dusa S, Crowe B, Danagoulian S, Danley T, Deconinck W, Defurne M, Desnault C, Di D, Dlamini M, Duer M, Duran B, Ent R, Fanelli C, Fuchey E, Gal C, Gaskell D, Georges F, Gilad S, Glamazdin O, Gnanvo K, Gramolin AV, Gray VM, Gu C, Habarakada A, Hague T, Hamad G, Hamilton D, Hamilton K, Hansen O, Hauenstein F, Hernandez AV, Henry W, Higinbotham DW, Holmstrom T, Horn T, Huang Y, Huber GM, Hyde C, Ibrahim H, Israel N, Jen CM, Jin K, Jones M, Kabir A, Karki B, Keppel C, Khachatryan V, King PM, Li S, Li W, Liu H, Liu J, Liyanage AH, Mack D, Magee J, Malace S, Mammei J, Markowitz P, Mayilyan S, McClellan E, Meddi F, Meekins D, Mesick K, Michaels R, Mkrtchyan A, Moffit B, Montgomery R, Myers LS, Nadel-Turonski P, Nazeer SJ, Nelyubin V, Nguyen D, Nuruzzaman N, Nycz M, Obrecht RF, Ohanyan K, Palatchi C, Pandey B, Park K, Park S, Peng C, Persio FD, Pomatsalyuk R, Pooser E, Puckett AJR, Punjabi V, Quinn B, Rahman S, Rashad MNH, Reimer PE, Riordan S, Roche J, Sapkota I, Sarty A, Sawatzky B, Saylor NH, Shabestari MH, Shahinyan A, Širca S, Smith GR, Sooriyaarachchilage S, Sparveris N, Spies R, Stefanko A, Su T, Subedi A, Sulkosky V, Sun A, Tan Y, Thorne L, Ton N, Tortorici F, Trotta R, Uniyal R, Urciuoli GM, Voutier E, Waidyawansa B, Wojtsekhowski B, Wood S, Yan X, Ye L, Ye ZH, Yero C, Zhang J, Zhao YX, Zhu P. Form Factors and Two-Photon Exchange in High-Energy Elastic Electron-Proton Scattering. PHYSICAL REVIEW LETTERS 2022; 128:102002. [PMID: 35333083 DOI: 10.1103/physrevlett.128.102002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 11/06/2021] [Accepted: 01/31/2022] [Indexed: 06/14/2023]
Abstract
We present new precision measurements of the elastic electron-proton scattering cross section for momentum transfer (Q^{2}) up to 15.75 (GeV/c)^{2}. Combined with existing data, these provide an improved extraction of the proton magnetic form factor at high Q^{2} and double the range over which a longitudinal or transverse separation of the cross section can be performed. The difference between our results and polarization data agrees with that observed at lower Q^{2} and attributed to hard two-photon exchange (TPE) effects, extending to 8 (GeV/c)^{2} the range of Q^{2} for which a discrepancy is established at >95% confidence. We use the discrepancy to quantify the size of TPE contributions needed to explain the cross section at high Q^{2}.
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Affiliation(s)
- M E Christy
- Hampton University, Hampton, Virginia 23669, USA
| | - T Gautam
- Hampton University, Hampton, Virginia 23669, USA
| | - L Ou
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - B Schmookler
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Y Wang
- William and Mary, Williamsburg, Virginia 23185, USA
| | - D Adikaram
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - Z Ahmed
- University of Regina, Regina, Saskatchewan S4S 0A2 Canada
| | - H Albataineh
- Texas A & M University, Kingsville, Texas 77843, USA
| | - S F Ali
- Catholic University of America, Washington, District of Columbia 20064, USA
| | - B Aljawrneh
- North Carolina A&T State University, Greensboro, North Carolina 27411, USA
- Al Zaytoonah University of Jordan, Amman 11733, Jordan
| | - K Allada
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - S L Allison
- Old Dominion University, Norfolk, Virginia 23529, USA
| | - S Alsalmi
- Kent State University, Kent, Ohio 44240, USA
| | - D Androic
- University of Zagreb, Trg Republike Hrvatske 14, 10000, Zagreb, Croatia
| | - K Aniol
- California State University, Los Angeles, Los Angeles, California 90032, USA
| | - J Annand
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - J Arrington
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - H Atac
- Temple University, Philadelphia, Pennsylvania 19122, USA
| | - T Averett
- William and Mary, Williamsburg, Virginia 23185, USA
| | | | - X Bai
- University of Virginia, Charlottesville, Virginia 232904, USA
| | - J Bane
- University of Tennessee, Knoxville, Tennessee 37996, USA
| | - S Barcus
- William and Mary, Williamsburg, Virginia 23185, USA
| | - K Bartlett
- William and Mary, Williamsburg, Virginia 23185, USA
| | - V Bellini
- Istituto Nazionale di Fisica Nucleare, Department of Physics and Astronomy, I-95123 Catania, Italy
| | | | - J Bericic
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - H Bhatt
- Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - D Bhetuwal
- Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - D Biswas
- Hampton University, Hampton, Virginia 23669, USA
| | - E Brash
- Christopher Newport University, Newport News, Virginia 23606, USA
| | - D Bulumulla
- Old Dominion University, Norfolk, Virginia 23529, USA
| | - C M Camacho
- Institut de Physique Nucleaire, 15 Rue Georges Clemenceau, 91400 Orsay, France
| | - J Campbell
- Dalhousie University, Nova Scotia NS B3H 4R2, Canada
| | - A Camsonne
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - M Carmignotto
- Catholic University of America, Washington, DC 20064, USA
| | - J Castellanos
- Florida International University, Miami, Florida 33199, USA
| | - C Chen
- Hampton University, Hampton, Virginia 23669, USA
| | - J-P Chen
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - T Chetry
- Ohio University, Athens, Ohio 45701, USA
| | - E Cisbani
- Istituto Nazionale di Fisica Nucleare - Sezione di Roma, P.le Aldo Moro, 2 - 00185 Roma, Italy
| | - B Clary
- University of Connecticut, Storrs, Connecticut 06269, USA
| | - E Cohen
- Tel Aviv University, Tel Aviv-Yafo 69978, Israel
| | - N Compton
- Ohio University, Athens, Ohio 45701, USA
| | - J C Cornejo
- William and Mary, Williamsburg, Virginia 23185, USA
- Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - S Covrig Dusa
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - B Crowe
- North Carolina Central University, Durham, North Carolina 27707, USA
| | - S Danagoulian
- North Carolina A&T State University, Greensboro, North Carolina 27411, USA
| | - T Danley
- Ohio University, Athens, Ohio 45701, USA
| | - W Deconinck
- William and Mary, Williamsburg, Virginia 23185, USA
| | - M Defurne
- CEA Saclay, 91191 Gif-sur-Yvette, France
| | - C Desnault
- Institut de Physique Nucleaire, 15 Rue Georges Clemenceau, 91400 Orsay, France
| | - D Di
- University of Virginia, Charlottesville, Virginia 232904, USA
| | - M Dlamini
- Ohio University, Athens, Ohio 45701, USA
| | - M Duer
- Tel Aviv University, Tel Aviv-Yafo 69978, Israel
| | - B Duran
- Temple University, Philadelphia, Pennsylvania 19122, USA
| | - R Ent
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - C Fanelli
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - E Fuchey
- University of Connecticut, Storrs, Connecticut 06269, USA
| | - C Gal
- University of Virginia, Charlottesville, Virginia 232904, USA
| | - D Gaskell
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - F Georges
- Ecole Centrale Paris, 3 Rue Joliot Curie, 91190 Gif-sur-Yvette, France
| | - S Gilad
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - O Glamazdin
- Kharkov Institute of Physics and Technology, Kharkov 61108, Ukraine
| | - K Gnanvo
- University of Virginia, Charlottesville, Virginia 232904, USA
| | - A V Gramolin
- Boston University, Boston, Massachusetts 02215, USA
| | - V M Gray
- William and Mary, Williamsburg, Virginia 23185, USA
| | - C Gu
- University of Virginia, Charlottesville, Virginia 232904, USA
| | - A Habarakada
- Hampton University, Hampton, Virginia 23669, USA
| | - T Hague
- Kent State University, Kent, Ohio 44240, USA
| | - G Hamad
- Ohio University, Athens, Ohio 45701, USA
| | - D Hamilton
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - K Hamilton
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - O Hansen
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - F Hauenstein
- Old Dominion University, Norfolk, Virginia 23529, USA
| | - A V Hernandez
- Catholic University of America, Washington, DC 20064, USA
| | - W Henry
- Temple University, Philadelphia, Pennsylvania 19122, USA
| | - D W Higinbotham
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - T Holmstrom
- Randolph Macon College, Ashland, Virginia 23005, USA
| | - T Horn
- Catholic University of America, Washington, DC 20064, USA
| | - Y Huang
- University of Virginia, Charlottesville, Virginia 232904, USA
| | - G M Huber
- University of Regina, Regina, Saskatchewan S4S 0A2 Canada
| | - C Hyde
- Old Dominion University, Norfolk, Virginia 23529, USA
| | - H Ibrahim
- Cairo University, Cairo, 12613, Egypt
| | - N Israel
- Ohio University, Athens, Ohio 45701, USA
| | - C-M Jen
- Virginia Polytechnic Institute and State University, Blacksburg, Virginia 234061, USA
| | - K Jin
- University of Virginia, Charlottesville, Virginia 232904, USA
| | - M Jones
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - A Kabir
- Kent State University, Kent, Ohio 44240, USA
| | - B Karki
- Ohio University, Athens, Ohio 45701, USA
| | - C Keppel
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - V Khachatryan
- Stony Brook, State University of New York, New York 11794, USA
- Cornell University, Ithaca, New York 14853, USA
| | - P M King
- Ohio University, Athens, Ohio 45701, USA
| | - S Li
- University of New Hampshire, Durham, New Hampshire 03824, USA
| | - W Li
- University of Regina, Regina, Saskatchewan S4S 0A2 Canada
| | - H Liu
- Columbia University, New York, New York 10027, USA
| | - J Liu
- University of Virginia, Charlottesville, Virginia 232904, USA
| | - A H Liyanage
- Hampton University, Hampton, Virginia 23669, USA
| | - D Mack
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - J Magee
- William and Mary, Williamsburg, Virginia 23185, USA
| | - S Malace
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - J Mammei
- University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - P Markowitz
- Florida International University, Miami, Florida 33199, USA
| | - S Mayilyan
- AANL, 2 Alikhanian Brothers Street, 0036 Yerevan, Armenia
| | - E McClellan
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - F Meddi
- Istituto Nazionale di Fisica Nucleare - Sezione di Roma, P.le Aldo Moro, 2 - 00185 Roma, Italy
| | - D Meekins
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - K Mesick
- Rutgers University, New Brunswick, New Jersey 08854, USA
| | - R Michaels
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - A Mkrtchyan
- Catholic University of America, Washington, DC 20064, USA
| | - B Moffit
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - R Montgomery
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - L S Myers
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - P Nadel-Turonski
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - S J Nazeer
- Hampton University, Hampton, Virginia 23669, USA
| | - V Nelyubin
- University of Virginia, Charlottesville, Virginia 232904, USA
| | - D Nguyen
- University of Virginia, Charlottesville, Virginia 232904, USA
| | - N Nuruzzaman
- Hampton University, Hampton, Virginia 23669, USA
| | - M Nycz
- Kent State University, Kent, Ohio 44240, USA
| | - R F Obrecht
- University of Connecticut, Storrs, Connecticut 06269, USA
| | - K Ohanyan
- AANL, 2 Alikhanian Brothers Street, 0036 Yerevan, Armenia
| | - C Palatchi
- University of Virginia, Charlottesville, Virginia 232904, USA
| | - B Pandey
- Hampton University, Hampton, Virginia 23669, USA
| | - K Park
- Old Dominion University, Norfolk, Virginia 23529, USA
| | - S Park
- Stony Brook, State University of New York, New York 11794, USA
| | - C Peng
- Duke University, Durham, North Carolina 27708, USA
| | - F D Persio
- Istituto Nazionale di Fisica Nucleare - Sezione di Roma, P.le Aldo Moro, 2 - 00185 Roma, Italy
| | - R Pomatsalyuk
- Kharkov Institute of Physics and Technology, Kharkov 61108, Ukraine
| | - E Pooser
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - A J R Puckett
- University of Connecticut, Storrs, Connecticut 06269, USA
| | - V Punjabi
- Norfolk State University, Norfolk, Virginia 23504, USA
| | - B Quinn
- Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - S Rahman
- University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - M N H Rashad
- Old Dominion University, Norfolk, Virginia 23529, USA
| | - P E Reimer
- Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - S Riordan
- Stony Brook, State University of New York, New York 11794, USA
| | - J Roche
- Ohio University, Athens, Ohio 45701, USA
| | - I Sapkota
- Catholic University of America, Washington, DC 20064, USA
| | - A Sarty
- Saint Mary's University, Halifax, Nova Scotia B3H 3C3, Canada
| | - B Sawatzky
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - N H Saylor
- Rensselaer Polytechnic Institute, Troy, New York 12180, USA
| | - M H Shabestari
- Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - A Shahinyan
- AANL, 2 Alikhanian Brothers Street, 0036 Yerevan, Armenia
| | - S Širca
- Faculty of Mathematics and Physics, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - G R Smith
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | | | - N Sparveris
- Temple University, Philadelphia, Pennsylvania 19122, USA
| | - R Spies
- University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - A Stefanko
- Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - T Su
- Kent State University, Kent, Ohio 44240, USA
| | - A Subedi
- Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - V Sulkosky
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - A Sun
- Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - Y Tan
- Shandong University, Shandong, Jinan 250100, China
| | - L Thorne
- Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - N Ton
- University of Virginia, Charlottesville, Virginia 232904, USA
| | - F Tortorici
- Istituto Nazionale di Fisica Nucleare, Department of Physics and Astronomy, I-95123 Catania, Italy
| | - R Trotta
- Duquesne University, Pittsburgh, Pennsylvania 15282, USA
| | - R Uniyal
- Catholic University of America, Washington, DC 20064, USA
| | - G M Urciuoli
- Istituto Nazionale di Fisica Nucleare - Sezione di Roma, P.le Aldo Moro, 2 - 00185 Roma, Italy
| | - E Voutier
- Institut de Physique Nucleaire, 15 Rue Georges Clemenceau, 91400 Orsay, France
| | - B Waidyawansa
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - B Wojtsekhowski
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - S Wood
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - X Yan
- Huangshan University, 44 Daizhen Road, Tunxi District, Huangshan, Anhui Province, China
| | - L Ye
- Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - Z H Ye
- University of Virginia, Charlottesville, Virginia 232904, USA
- Tsinghua University, 30 Shuangqing Rd, Haidian District, Beijing 100190, China
| | - C Yero
- Florida International University, Miami, Florida 33199, USA
| | - J Zhang
- University of Virginia, Charlottesville, Virginia 232904, USA
| | - Y X Zhao
- Stony Brook, State University of New York, New York 11794, USA
| | - P Zhu
- University of Science and Technology of China, Hefei, Anhui 230026, China
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2
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Bernauer JC, Schmidt A, Henderson BS, Ice LD, Khaneft D, O'Connor C, Russell R, Akopov N, Alarcon R, Ates O, Avetisyan A, Beck R, Belostotski S, Bessuille J, Brinker F, Calarco JR, Carassiti V, Cisbani E, Ciullo G, Contalbrigo M, De Leo R, Diefenbach J, Donnelly TW, Dow K, Elbakian G, Eversheim PD, Frullani S, Funke C, Gavrilov G, Gläser B, Görrissen N, Hasell DK, Hauschildt J, Hoffmeister P, Holler Y, Ihloff E, Izotov A, Kaiser R, Karyan G, Kelsey J, Kiselev A, Klassen P, Krivshich A, Kohl M, Lehmann I, Lenisa P, Lenz D, Lumsden S, Ma Y, Maas F, Marukyan H, Miklukho O, Milner RG, Movsisyan A, Murray M, Naryshkin Y, Perez Benito R, Perrino R, Redwine RP, Rodríguez Piñeiro D, Rosner G, Schneekloth U, Seitz B, Statera M, Thiel A, Vardanyan H, Veretennikov D, Vidal C, Winnebeck A, Yeganov V. Measurement of the Charge-Averaged Elastic Lepton-Proton Scattering Cross Section by the OLYMPUS Experiment. PHYSICAL REVIEW LETTERS 2021; 126:162501. [PMID: 33961478 DOI: 10.1103/physrevlett.126.162501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 03/17/2021] [Accepted: 03/23/2021] [Indexed: 06/12/2023]
Abstract
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.
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Affiliation(s)
- J C Bernauer
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - A Schmidt
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - B S Henderson
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - L D Ice
- Arizona State University, Tempe, Arizona 85287, USA
| | - D Khaneft
- Johannes Gutenberg-Universität, Mainz, Germany
| | - C O'Connor
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - R Russell
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - N Akopov
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), Yerevan, Armenia
| | - R Alarcon
- Arizona State University, Tempe, Arizona 85287, USA
| | - O Ates
- Hampton University, Hampton, Virginia 23668, USA
| | - A Avetisyan
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), Yerevan, Armenia
| | - R Beck
- Rheinische Friedrich-Wilhelms-Universität, Bonn, Germany
| | - S Belostotski
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - J Bessuille
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - F Brinker
- Deutsches Elektronen-Synchrotron, Hamburg, Germany
| | - J R Calarco
- University of New Hampshire, Durham, New Hampshire 03824, USA
| | - V Carassiti
- Università degli Studi di Ferrara and Istituto Nazionale di Fisica Nucleare sezione di Ferrara, Ferrara, Italy
| | - E Cisbani
- Istituto Nazionale di Fisica Nucleare sezione di Roma and Istituto Superiore di Sanità, Rome, Italy
| | - G Ciullo
- Università degli Studi di Ferrara and Istituto Nazionale di Fisica Nucleare sezione di Ferrara, Ferrara, Italy
| | - M Contalbrigo
- Università degli Studi di Ferrara and Istituto Nazionale di Fisica Nucleare sezione di Ferrara, Ferrara, Italy
| | - R De Leo
- Istituto Nazionale di Fisica Nucleare sezione di Bari, Bari, Italy
| | - J Diefenbach
- Hampton University, Hampton, Virginia 23668, USA
| | - T W Donnelly
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - K Dow
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - G Elbakian
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), Yerevan, Armenia
| | - P D Eversheim
- Rheinische Friedrich-Wilhelms-Universität, Bonn, Germany
| | - S Frullani
- Istituto Nazionale di Fisica Nucleare sezione di Roma and Istituto Superiore di Sanità, Rome, Italy
| | - Ch Funke
- Rheinische Friedrich-Wilhelms-Universität, Bonn, Germany
| | - G Gavrilov
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - B Gläser
- Johannes Gutenberg-Universität, Mainz, Germany
| | - N Görrissen
- Deutsches Elektronen-Synchrotron, Hamburg, Germany
| | - D K Hasell
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - J Hauschildt
- Deutsches Elektronen-Synchrotron, Hamburg, Germany
| | - Ph Hoffmeister
- Rheinische Friedrich-Wilhelms-Universität, Bonn, Germany
| | - Y Holler
- Deutsches Elektronen-Synchrotron, Hamburg, Germany
| | - E Ihloff
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - A Izotov
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - R Kaiser
- University of Glasgow, Glasgow, United Kingdom
| | - G Karyan
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), Yerevan, Armenia
| | - J Kelsey
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - A Kiselev
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - P Klassen
- Rheinische Friedrich-Wilhelms-Universität, Bonn, Germany
| | - A Krivshich
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - M Kohl
- Hampton University, Hampton, Virginia 23668, USA
| | - I Lehmann
- University of Glasgow, Glasgow, United Kingdom
| | - P Lenisa
- Università degli Studi di Ferrara and Istituto Nazionale di Fisica Nucleare sezione di Ferrara, Ferrara, Italy
| | - D Lenz
- Deutsches Elektronen-Synchrotron, Hamburg, Germany
| | - S Lumsden
- University of Glasgow, Glasgow, United Kingdom
| | - Y Ma
- Johannes Gutenberg-Universität, Mainz, Germany
| | - F Maas
- Johannes Gutenberg-Universität, Mainz, Germany
| | - H Marukyan
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), Yerevan, Armenia
| | - O Miklukho
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - R G Milner
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - A Movsisyan
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), Yerevan, Armenia
- Università degli Studi di Ferrara and Istituto Nazionale di Fisica Nucleare sezione di Ferrara, Ferrara, Italy
| | - M Murray
- University of Glasgow, Glasgow, United Kingdom
| | - Y Naryshkin
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | | | - R Perrino
- Istituto Nazionale di Fisica Nucleare sezione di Bari, Bari, Italy
| | - R P Redwine
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | | | - G Rosner
- University of Glasgow, Glasgow, United Kingdom
| | | | - B Seitz
- University of Glasgow, Glasgow, United Kingdom
| | - M Statera
- Università degli Studi di Ferrara and Istituto Nazionale di Fisica Nucleare sezione di Ferrara, Ferrara, Italy
| | - A Thiel
- Rheinische Friedrich-Wilhelms-Universität, Bonn, Germany
| | - H Vardanyan
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), Yerevan, Armenia
| | | | - C Vidal
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - A Winnebeck
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - V Yeganov
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), Yerevan, Armenia
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3
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Borah K, Hill RJ, Lee G, Tomalak O. Parametrization and applications of the low-
Q2
nucleon vector form factors. Int J Clin Exp Med 2020. [DOI: 10.1103/physrevd.102.074012] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Tomasi-Gustafsson E, Bytev V. Critical analysis of recent results on electron and positron elastic scattering on proton. EPJ WEB OF CONFERENCES 2019. [DOI: 10.1051/epjconf/201920401009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Recent data on the cross section ratio for electron and positron elastic scattering on protons are discussed. A deviation from unity of this ratio constitutes a model independent signature of charge-odd contributions that arise from mechanisms beyond the one-photon approximation, as the exchange of two photons. The relevance of this issue is related to that fact that the information on the proton structure from lepton elastic (and inelastic) scattering holds only within a formalism based on the one photon exchange approximation. The present analysis shows that the deviations of the data from unity and from a previously developed theoretical approach lie within the theoretical and experimental errors. The data suggest that other reasons for explanation of the discrepancy between the electromagnetic proton form factors extracted from the experiments according to the polarized and the unpolarized methods are more likely.
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5
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Chen HY, Zhou HQ. Two-photon exchange effects in
e+e−→π+π−
and timelike pion electromagnetic form factor. Int J Clin Exp Med 2018. [DOI: 10.1103/physrevd.98.054003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Henderson BS, Ice LD, Khaneft D, O'Connor C, Russell R, Schmidt A, Bernauer JC, Kohl M, Akopov N, Alarcon R, Ates O, Avetisyan A, Beck R, Belostotski S, Bessuille J, Brinker F, Calarco JR, Carassiti V, Cisbani E, Ciullo G, Contalbrigo M, De Leo R, Diefenbach J, Donnelly TW, Dow K, Elbakian G, Eversheim PD, Frullani S, Funke C, Gavrilov G, Gläser B, Görrissen N, Hasell DK, Hauschildt J, Hoffmeister P, Holler Y, Ihloff E, Izotov A, Kaiser R, Karyan G, Kelsey J, Kiselev A, Klassen P, Krivshich A, Lehmann I, Lenisa P, Lenz D, Lumsden S, Ma Y, Maas F, Marukyan H, Miklukho O, Milner RG, Movsisyan A, Murray M, Naryshkin Y, Perez Benito R, Perrino R, Redwine RP, Rodríguez Piñeiro D, Rosner G, Schneekloth U, Seitz B, Statera M, Thiel A, Vardanyan H, Veretennikov D, Vidal C, Winnebeck A, Yeganov V. Hard Two-Photon Contribution to Elastic Lepton-Proton Scattering Determined by the OLYMPUS Experiment. PHYSICAL REVIEW LETTERS 2017; 118:092501. [PMID: 28306315 DOI: 10.1103/physrevlett.118.092501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Indexed: 06/06/2023]
Abstract
The OLYMPUS Collaboration reports on a precision measurement of the positron-proton to electron-proton elastic cross section ratio, R_{2γ}, a direct measure of the contribution of hard two-photon exchange to the elastic cross section. In the OLYMPUS measurement, 2.01 GeV electron and positron beams were directed through a hydrogen gas target internal to the DORIS storage ring at DESY. A toroidal magnetic spectrometer instrumented with drift chambers and time-of-flight scintillators detected elastically scattered leptons in coincidence with recoiling protons over a scattering angle range of ≈20° to 80°. The relative luminosity between the two beam species was monitored using tracking telescopes of interleaved gas electron multiplier and multiwire proportional chamber detectors at 12°, as well as symmetric Møller or Bhabha calorimeters at 1.29°. A total integrated luminosity of 4.5 fb^{-1} was collected. In the extraction of R_{2γ}, radiative effects were taken into account using a Monte Carlo generator to simulate the convolutions of internal bremsstrahlung with experiment-specific conditions such as detector acceptance and reconstruction efficiency. The resulting values of R_{2γ}, presented here for a wide range of virtual photon polarization 0.456<ε<0.978, are smaller than some hadronic two-photon exchange calculations predict, but are in reasonable agreement with a subtracted dispersion model and a phenomenological fit to the form factor data.
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Affiliation(s)
- B S Henderson
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - L D Ice
- Arizona State University, Tempe, Arizona 85281, USA
| | - D Khaneft
- Johannes Gutenberg-Universität, 55099 Mainz, Germany
| | - C O'Connor
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - R Russell
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - A Schmidt
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - J C Bernauer
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - M Kohl
- Hampton University, Hampton, Virginia 23668, USA
| | - N Akopov
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), 0036 Yerevan, Armenia
| | - R Alarcon
- Arizona State University, Tempe, Arizona 85281, USA
| | - O Ates
- Hampton University, Hampton, Virginia 23668, USA
| | - A Avetisyan
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), 0036 Yerevan, Armenia
| | - R Beck
- Rheinische Friedrich-Wilhelms-Universität, 53113 Bonn, Germany
| | - S Belostotski
- Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - J Bessuille
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - F Brinker
- Deutsches Elektronen-Synchrotron, 22603 Hamburg, Germany
| | - J R Calarco
- University of New Hampshire, Durham, New Hampshire 03824, USA
| | - V Carassiti
- Università degli Studi di Ferrara and Istituto Nazionale di Fisica Nucleare sezione di Ferrara, 44122 Ferrara, Italy
| | - E Cisbani
- Istituto Nazionale di Fisica Nucleare sezione di Roma and Istituto Superiore di Sanità, 00185 Rome, Italy
| | - G Ciullo
- Università degli Studi di Ferrara and Istituto Nazionale di Fisica Nucleare sezione di Ferrara, 44122 Ferrara, Italy
| | - M Contalbrigo
- Università degli Studi di Ferrara and Istituto Nazionale di Fisica Nucleare sezione di Ferrara, 44122 Ferrara, Italy
| | - R De Leo
- Istituto Nazionale di Fisica Nucleare sezione di Bari, 70126 Bari, Italy
| | - J Diefenbach
- Hampton University, Hampton, Virginia 23668, USA
| | - T W Donnelly
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - K Dow
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - G Elbakian
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), 0036 Yerevan, Armenia
| | - P D Eversheim
- Rheinische Friedrich-Wilhelms-Universität, 53113 Bonn, Germany
| | - S Frullani
- Istituto Nazionale di Fisica Nucleare sezione di Roma and Istituto Superiore di Sanità, 00185 Rome, Italy
| | - Ch Funke
- Rheinische Friedrich-Wilhelms-Universität, 53113 Bonn, Germany
| | - G Gavrilov
- Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - B Gläser
- Johannes Gutenberg-Universität, 55099 Mainz, Germany
| | - N Görrissen
- Deutsches Elektronen-Synchrotron, 22603 Hamburg, Germany
| | - D K Hasell
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - J Hauschildt
- Deutsches Elektronen-Synchrotron, 22603 Hamburg, Germany
| | - Ph Hoffmeister
- Rheinische Friedrich-Wilhelms-Universität, 53113 Bonn, Germany
| | - Y Holler
- Deutsches Elektronen-Synchrotron, 22603 Hamburg, Germany
| | - E Ihloff
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - A Izotov
- Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - R Kaiser
- University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - G Karyan
- Deutsches Elektronen-Synchrotron, 22603 Hamburg, Germany
| | - J Kelsey
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - A Kiselev
- Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - P Klassen
- Rheinische Friedrich-Wilhelms-Universität, 53113 Bonn, Germany
| | - A Krivshich
- Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - I Lehmann
- University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - P Lenisa
- Università degli Studi di Ferrara and Istituto Nazionale di Fisica Nucleare sezione di Ferrara, 44122 Ferrara, Italy
| | - D Lenz
- Deutsches Elektronen-Synchrotron, 22603 Hamburg, Germany
| | - S Lumsden
- University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Y Ma
- Johannes Gutenberg-Universität, 55099 Mainz, Germany
| | - F Maas
- Johannes Gutenberg-Universität, 55099 Mainz, Germany
| | - H Marukyan
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), 0036 Yerevan, Armenia
| | - O Miklukho
- Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - R G Milner
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - A Movsisyan
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), 0036 Yerevan, Armenia
| | - M Murray
- University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Y Naryshkin
- Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | | | - R Perrino
- Istituto Nazionale di Fisica Nucleare sezione di Bari, 70126 Bari, Italy
| | - R P Redwine
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | | | - G Rosner
- University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - U Schneekloth
- Deutsches Elektronen-Synchrotron, 22603 Hamburg, Germany
| | - B Seitz
- University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - M Statera
- Università degli Studi di Ferrara and Istituto Nazionale di Fisica Nucleare sezione di Ferrara, 44122 Ferrara, Italy
| | - A Thiel
- Rheinische Friedrich-Wilhelms-Universität, 53113 Bonn, Germany
| | - H Vardanyan
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), 0036 Yerevan, Armenia
| | - D Veretennikov
- Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - C Vidal
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - A Winnebeck
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - V Yeganov
- Alikhanyan National Science Laboratory (Yerevan Physics Institute), 0036 Yerevan, Armenia
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Tomasi-Gustafsson E, Pacetti S, Bianconi A. Highlights in the hadron electromagnetic structure. EPJ WEB OF CONFERENCES 2017. [DOI: 10.1051/epjconf/201713801003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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9
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Gutsche T, Lyubovitskij VE, Schmidt I, Vega A. Nucleon structure in a light-front quark model consistent with quark counting rules and data. Int J Clin Exp Med 2015. [DOI: 10.1103/physrevd.91.054028] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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10
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Adikaram D, Rimal D, Weinstein LB, Raue B, Khetarpal P, Bennett RP, Arrington J, Brooks WK, Adhikari KP, Afanasev AV, Amaryan MJ, Anderson MD, Anefalos Pereira S, Avakian H, Ball J, Battaglieri M, Bedlinskiy I, Biselli AS, Bono J, Boiarinov S, Briscoe WJ, Burkert VD, Carman DS, Careccia S, Celentano A, Chandavar S, Charles G, Colaneri L, Cole PL, Contalbrigo M, Crede V, D'Angelo A, Dashyan N, De Vita R, De Sanctis E, Deur A, Djalali C, Dodge GE, Dupre R, Egiyan H, El Alaoui A, El Fassi L, Elouadrhiri L, Eugenio P, Fedotov G, Fegan S, Filippi A, Fleming JA, Fradi A, Garillon B, Gilfoyle GP, Giovanetti KL, Girod FX, Goetz JT, Gohn W, Golovatch E, Gothe RW, Griffioen KA, Guegan B, Guidal M, Guo L, Hafidi K, Hakobyan H, Hanretty C, Harrison N, Hattawy M, Hicks K, Holtrop M, Hughes SM, Hyde CE, Ilieva Y, Ireland DG, Ishkhanov BS, Jenkins D, Jiang H, Jo HS, Joo K, Joosten S, Kalantarians N, Keller D, Khandaker M, Kim A, Kim W, Klein A, Klein FJ, Koirala S, Kubarovsky V, Kuhn SE, Livingston K, Lu HY, MacGregor IJD, Markov N, Mattione P, Mayer M, McKinnon B, Mestayer MD, Meyer CA, Mirazita M, Mokeev V, Montgomery RA, Moody CI, Moutarde H, Movsisyan A, Camacho CM, Nadel-Turonski P, Niccolai S, Niculescu G, Osipenko M, Ostrovidov AI, Park K, Pasyuk E, Peña C, Pisano S, Pogorelko O, Price JW, Procureur S, Prok Y, Protopopescu D, Puckett AJR, Ripani M, Rizzo A, Rosner G, Rossi P, Roy P, Sabatié F, Salgado C, Schott D, Schumacher RA, Seder E, Sharabian YG, Simonyan A, Skorodumina I, Smith ES, Smith GD, Sober DI, Sokhan D, Sparveris N, Stepanyan S, Stoler P, Strauch S, Sytnik V, Taiuti M, Tian Y, Trivedi A, Ungaro M, Voskanyan H, Voutier E, Walford NK, Watts DP, Wei X, Wood MH, Zachariou N, Zana L, Zhang J, Zhao ZW, Zonta I. Towards a resolution of the proton form factor problem: new electron and positron scattering data. PHYSICAL REVIEW LETTERS 2015; 114:062003. [PMID: 25723209 DOI: 10.1103/physrevlett.114.062003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Indexed: 06/04/2023]
Abstract
There is a significant discrepancy between the values of the proton electric form factor, G(E)(p), extracted using unpolarized and polarized electron scattering. Calculations predict that small two-photon exchange (TPE) contributions can significantly affect the extraction of G(E)(p) from the unpolarized electron-proton cross sections. We determined the TPE contribution by measuring the ratio of positron-proton to electron-proton elastic scattering cross sections using a simultaneous, tertiary electron-positron beam incident on a liquid hydrogen target and detecting the scattered particles in the Jefferson Lab CLAS detector. This novel technique allowed us to cover a wide range in virtual photon polarization (ϵ) and momentum transfer (Q(2)) simultaneously, as well as to cancel luminosity-related systematic errors. The cross section ratio increases with decreasing ϵ at Q(2)=1.45 GeV(2). This measurement is consistent with the size of the form factor discrepancy at Q(2)≈1.75 GeV(2) and with hadronic calculations including nucleon and Δ intermediate states, which have been shown to resolve the discrepancy up to 2-3 GeV(2).
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Affiliation(s)
- D Adikaram
- Old Dominion University, Norfolk, Virginia 23529, USA
| | - D Rimal
- Florida International University, Miami, Florida 33199, USA
| | - L B Weinstein
- Old Dominion University, Norfolk, Virginia 23529, USA
| | - B Raue
- Florida International University, Miami, Florida 33199, USA
| | - P Khetarpal
- Florida International University, Miami, Florida 33199, USA
| | - R P Bennett
- Old Dominion University, Norfolk, Virginia 23529, USA
| | - J Arrington
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - W K Brooks
- Universidad Técnica Federico Santa María, Casilla 110-V Valparaíso, Chile
| | - K P Adhikari
- Old Dominion University, Norfolk, Virginia 23529, USA
| | - A V Afanasev
- The George Washington University, Washington, DC 20052, USA
| | - M J Amaryan
- Old Dominion University, Norfolk, Virginia 23529, USA
| | - M D Anderson
- University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | | | - H Avakian
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - J Ball
- CEA, Centre de Saclay, Irfu/Service de Physique Nucléaire, 91191 Gif-sur-Yvette, France
| | | | - I Bedlinskiy
- Institute of Theoretical and Experimental Physics, Moscow 117259, Russia
| | - A S Biselli
- Fairfield University, Fairfield, Connecticut 06824, USA
| | - J Bono
- Florida International University, Miami, Florida 33199, USA
| | - S Boiarinov
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - W J Briscoe
- The George Washington University, Washington, DC 20052, USA
| | - V D Burkert
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - D S Carman
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - S Careccia
- Old Dominion University, Norfolk, Virginia 23529, USA
| | - A Celentano
- INFN, Sezione di Genova, 16146 Genova, Italy
| | | | - G Charles
- Institut de Physique Nucléaire, CNRS/IN2P3 and Université Paris Sud, Orsay, France
| | - L Colaneri
- INFN, Sezione di Roma Tor Vergata, 00133 Rome, Italy and Universita' di Roma Tor Vergata, 00133 Rome, Italy
| | - P L Cole
- Idaho State University, Pocatello, Idaho 83209, USA
| | | | - V Crede
- Florida State University, Tallahassee, Florida 32306, USA
| | - A D'Angelo
- INFN, Sezione di Roma Tor Vergata, 00133 Rome, Italy and Universita' di Roma Tor Vergata, 00133 Rome, Italy
| | - N Dashyan
- Yerevan Physics Institute, 375036 Yerevan, Armenia
| | - R De Vita
- INFN, Sezione di Genova, 16146 Genova, Italy
| | - E De Sanctis
- INFN, Laboratori Nazionali di Frascati, 00044 Frascati, Italy
| | - A Deur
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - C Djalali
- University of South Carolina, Columbia, South Carolina 29208, USA
| | - G E Dodge
- Old Dominion University, Norfolk, Virginia 23529, USA
| | - R Dupre
- Argonne National Laboratory, Argonne, Illinois 60439, USA and Institut de Physique Nucléaire, CNRS/IN2P3 and Université Paris Sud, Orsay, France
| | - H Egiyan
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - A El Alaoui
- Argonne National Laboratory, Argonne, Illinois 60439, USA and Universidad Técnica Federico Santa María, Casilla 110-V Valparaíso, Chile
| | - L El Fassi
- Old Dominion University, Norfolk, Virginia 23529, USA and Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - L Elouadrhiri
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - P Eugenio
- Florida State University, Tallahassee, Florida 32306, USA
| | - G Fedotov
- Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 119234 Moscow, Russia and University of South Carolina, Columbia, South Carolina 29208, USA
| | - S Fegan
- INFN, Sezione di Genova, 16146 Genova, Italy and University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - A Filippi
- INFN, sez. di Torino, 10125 Torino, Italy
| | - J A Fleming
- Edinburgh University, Edinburgh EH9 3JZ, United Kingdom
| | - A Fradi
- Institut de Physique Nucléaire, CNRS/IN2P3 and Université Paris Sud, Orsay, France
| | - B Garillon
- Institut de Physique Nucléaire, CNRS/IN2P3 and Université Paris Sud, Orsay, France
| | - G P Gilfoyle
- University of Richmond, Richmond, Virginia 23173, USA
| | - K L Giovanetti
- James Madison University, Harrisonburg, Virginia 22807, USA
| | - F X Girod
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - J T Goetz
- Ohio University, Athens, Ohio 45701, USA
| | - W Gohn
- University of Connecticut, Storrs, Connecticut 06269, USA
| | - E Golovatch
- Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 119234 Moscow, Russia
| | - R W Gothe
- University of South Carolina, Columbia, South Carolina 29208, USA
| | - K A Griffioen
- College of William and Mary, Williamsburg, Virginia 23187-8795, USA
| | - B Guegan
- Institut de Physique Nucléaire, CNRS/IN2P3 and Université Paris Sud, Orsay, France
| | - M Guidal
- Institut de Physique Nucléaire, CNRS/IN2P3 and Université Paris Sud, Orsay, France
| | - L Guo
- Florida International University, Miami, Florida 33199, USA
| | - K Hafidi
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - H Hakobyan
- Universidad Técnica Federico Santa María, Casilla 110-V Valparaíso, Chile and Yerevan Physics Institute, 375036 Yerevan, Armenia
| | - C Hanretty
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - N Harrison
- University of Connecticut, Storrs, Connecticut 06269, USA
| | - M Hattawy
- Institut de Physique Nucléaire, CNRS/IN2P3 and Université Paris Sud, Orsay, France
| | - K Hicks
- Ohio University, Athens, Ohio 45701, USA
| | - M Holtrop
- University of New Hampshire, Durham, New Hampshire 03824-3568, USA
| | - S M Hughes
- Edinburgh University, Edinburgh EH9 3JZ, United Kingdom
| | - C E Hyde
- Old Dominion University, Norfolk, Virginia 23529, USA
| | - Y Ilieva
- University of South Carolina, Columbia, South Carolina 29208, USA
| | - D G Ireland
- University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - B S Ishkhanov
- Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 119234 Moscow, Russia
| | - D Jenkins
- Virginia Tech, Blacksburg, Virginia 24061-0435, USA
| | - H Jiang
- University of South Carolina, Columbia, South Carolina 29208, USA
| | - H S Jo
- Institut de Physique Nucléaire, CNRS/IN2P3 and Université Paris Sud, Orsay, France
| | - K Joo
- University of Connecticut, Storrs, Connecticut 06269, USA
| | - S Joosten
- Temple University, Philadelphia, Pennsylvania 19122, USA
| | - N Kalantarians
- University of Virginia, Charlottesville, Virginia 22901, USA
| | - D Keller
- University of Virginia, Charlottesville, Virginia 22901, USA
| | - M Khandaker
- Idaho State University, Pocatello, Idaho 83209, USA and Norfolk State University, Norfolk, Virginia 23504, USA
| | - A Kim
- University of Connecticut, Storrs, Connecticut 06269, USA
| | - W Kim
- Kyungpook National University, Daegu 702-701, Republic of Korea
| | - A Klein
- Old Dominion University, Norfolk, Virginia 23529, USA
| | - F J Klein
- Catholic University of America, Washington, D.C. 20064, USA
| | - S Koirala
- Old Dominion University, Norfolk, Virginia 23529, USA
| | - V Kubarovsky
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - S E Kuhn
- Old Dominion University, Norfolk, Virginia 23529, USA
| | - K Livingston
- University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - H Y Lu
- Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA and University of South Carolina, Columbia, South Carolina 29208, USA
| | | | - N Markov
- University of Connecticut, Storrs, Connecticut 06269, USA
| | - P Mattione
- Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - M Mayer
- Old Dominion University, Norfolk, Virginia 23529, USA
| | - B McKinnon
- University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - M D Mestayer
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - C A Meyer
- Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - M Mirazita
- INFN, Laboratori Nazionali di Frascati, 00044 Frascati, Italy
| | - V Mokeev
- Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 119234 Moscow, Russia and Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - R A Montgomery
- INFN, Laboratori Nazionali di Frascati, 00044 Frascati, Italy
| | - C I Moody
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - H Moutarde
- CEA, Centre de Saclay, Irfu/Service de Physique Nucléaire, 91191 Gif-sur-Yvette, France
| | - A Movsisyan
- INFN, Sezione di Ferrara, 44100 Ferrara, Italy
| | - C Munoz Camacho
- Institut de Physique Nucléaire, CNRS/IN2P3 and Université Paris Sud, Orsay, France
| | - P Nadel-Turonski
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - S Niccolai
- Institut de Physique Nucléaire, CNRS/IN2P3 and Université Paris Sud, Orsay, France
| | - G Niculescu
- James Madison University, Harrisonburg, Virginia 22807, USA
| | - M Osipenko
- INFN, Sezione di Genova, 16146 Genova, Italy
| | - A I Ostrovidov
- Florida State University, Tallahassee, Florida 32306, USA
| | - K Park
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - E Pasyuk
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - C Peña
- Universidad Técnica Federico Santa María, Casilla 110-V Valparaíso, Chile
| | - S Pisano
- INFN, Laboratori Nazionali di Frascati, 00044 Frascati, Italy and Institut de Physique Nucléaire, CNRS/IN2P3 and Université Paris Sud, Orsay, France
| | - O Pogorelko
- Institute of Theoretical and Experimental Physics, Moscow 117259, Russia
| | - J W Price
- California State University, Dominguez Hills, Carson, California 90747, USA
| | - S Procureur
- CEA, Centre de Saclay, Irfu/Service de Physique Nucléaire, 91191 Gif-sur-Yvette, France
| | - Y Prok
- Old Dominion University, Norfolk, Virginia 23529, USA and Christopher Newport University, Newport News, Virginia 23606, USA
| | | | - A J R Puckett
- University of Connecticut, Storrs, Connecticut 06269, USA
| | - M Ripani
- INFN, Sezione di Genova, 16146 Genova, Italy
| | - A Rizzo
- INFN, Sezione di Roma Tor Vergata, 00133 Rome, Italy and Universita' di Roma Tor Vergata, 00133 Rome, Italy
| | - G Rosner
- University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - P Rossi
- INFN, Laboratori Nazionali di Frascati, 00044 Frascati, Italy and Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - P Roy
- Florida State University, Tallahassee, Florida 32306, USA
| | - F Sabatié
- CEA, Centre de Saclay, Irfu/Service de Physique Nucléaire, 91191 Gif-sur-Yvette, France
| | - C Salgado
- Norfolk State University, Norfolk, Virginia 23504, USA
| | - D Schott
- Florida International University, Miami, Florida 33199, USA and The George Washington University, Washington, DC 20052, USA
| | - R A Schumacher
- Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - E Seder
- University of Connecticut, Storrs, Connecticut 06269, USA
| | - Y G Sharabian
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - A Simonyan
- Yerevan Physics Institute, 375036 Yerevan, Armenia
| | - I Skorodumina
- Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 119234 Moscow, Russia and University of South Carolina, Columbia, South Carolina 29208, USA
| | - E S Smith
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - G D Smith
- Edinburgh University, Edinburgh EH9 3JZ, United Kingdom and University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - D I Sober
- Catholic University of America, Washington, D.C. 20064, USA
| | - D Sokhan
- University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - N Sparveris
- Temple University, Philadelphia, Pennsylvania 19122, USA
| | - S Stepanyan
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - P Stoler
- Rensselaer Polytechnic Institute, Troy, New York 12180, USA
| | - S Strauch
- University of South Carolina, Columbia, South Carolina 29208, USA
| | - V Sytnik
- Universidad Técnica Federico Santa María, Casilla 110-V Valparaíso, Chile
| | - M Taiuti
- Università di Genova, 16146 Genova, Italy
| | - Ye Tian
- University of South Carolina, Columbia, South Carolina 29208, USA
| | - A Trivedi
- University of South Carolina, Columbia, South Carolina 29208, USA
| | - M Ungaro
- University of Connecticut, Storrs, Connecticut 06269, USA and Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - H Voskanyan
- Yerevan Physics Institute, 375036 Yerevan, Armenia
| | - E Voutier
- LPSC, Université Grenoble-Alpes, CNRS/IN2P3, Grenoble, France
| | - N K Walford
- Catholic University of America, Washington, D.C. 20064, USA
| | - D P Watts
- Edinburgh University, Edinburgh EH9 3JZ, United Kingdom
| | - X Wei
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - M H Wood
- Canisius College, Buffalo, New York 14208, USA
| | - N Zachariou
- The George Washington University, Washington, DC 20052, USA and University of South Carolina, Columbia, South Carolina 29208, USA
| | - L Zana
- University of New Hampshire, Durham, New Hampshire 03824-3568, USA and Edinburgh University, Edinburgh EH9 3JZ, United Kingdom
| | - J Zhang
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
| | - Z W Zhao
- Old Dominion University, Norfolk, Virginia 23529, USA and Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA and University of Virginia, Charlottesville, Virginia 22901, USA
| | - I Zonta
- INFN, Sezione di Roma Tor Vergata, 00133 Rome, Italy and Universita' di Roma Tor Vergata, 00133 Rome, Italy
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11
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Tomasi-Gustafsson E. Proton electromagnetic form factors: present status and future perspectives at PANDA. EPJ WEB OF CONFERENCES 2015. [DOI: 10.1051/epjconf/20159501015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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12
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Selyugin O. Models of parton distributions and the description of form factors of nucleon. Int J Clin Exp Med 2014. [DOI: 10.1103/physrevd.89.093007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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13
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Punjabi V, Perdrisat CF. The Proton Form Factor Ratio Measurements at Jefferson Lab. EPJ WEB OF CONFERENCES 2014. [DOI: 10.1051/epjconf/20146606019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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14
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Giusa A, Bellini V, Mammoliti F, Russo G, Sperduto M, Sutera C, Cisbani E, Garibaldi F, Urciuoli G, Capogni M, Cates G, de Jager K, Wojtsekhowski B. Nucleon form factor studies at JLab. Appl Radiat Isot 2011; 69:1125-7. [DOI: 10.1016/j.apradiso.2010.11.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Revised: 11/07/2010] [Accepted: 11/09/2010] [Indexed: 11/29/2022]
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15
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Meziane M, Brash EJ, Gilman R, Jones MK, Luo W, Pentchev L, Perdrisat CF, Puckett AJR, Punjabi V, Wesselmann FR, Ahmidouch A, Albayrak I, Aniol KA, Arrington J, Asaturyan A, Ates O, Baghdasaryan H, Benmokhtar F, Bertozzi W, Bimbot L, Bosted P, Boeglin W, Butuceanu C, Carter P, Chernenko S, Christy E, Commisso M, Cornejo JC, Covrig S, Danagoulian S, Daniel A, Davidenko A, Day D, Dhamija S, Dutta D, Ent R, Frullani S, Fenker H, Frlez E, Garibaldi F, Gaskell D, Gilad S, Goncharenko Y, Hafidi K, Hamilton D, Higinbotham DW, Hinton W, Horn T, Hu B, Huang J, Huber GM, Jensen E, Kang H, Keppel C, Khandaker M, King P, Kirillov D, Kohl M, Kravtsov V, Kumbartzki G, Li Y, Mamyan V, Margaziotis DJ, Markowitz P, Marsh A, Matulenko Y, Maxwell J, Mbianda G, Meekins D, Melnik Y, Miller J, Mkrtchyan A, Mkrtchyan H, Moffit B, Moreno O, Mulholland J, Narayan A, Nedev S, Piasetzky E, Pierce W, Piskunov NM, Prok Y, Ransome RD, Razin DS, Reimer PE, Reinhold J, Rondon O, Shabestari M, Shahinyan A, Shestermanov K, Širca S, Sitnik I, Smykov L, Smith G, Solovyev L, Solvignon P, Subedi R, Suleiman R, Tomasi-Gustafsson E, Vasiliev A, Vanderhaeghen M, Veilleux M, Wojtsekhowski BB, Wood S, Ye Z, Zanevsky Y, Zhang X, Zhang Y, Zheng X, Zhu L. Search for effects beyond the born approximation in polarization transfer observables in e(over→)p elastic scattering. PHYSICAL REVIEW LETTERS 2011; 106:132501. [PMID: 21520982 DOI: 10.1103/physrevlett.106.132501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Indexed: 05/30/2023]
Abstract
Intensive theoretical and experimental efforts over the past decade have aimed at explaining the discrepancy between data for the proton electric to magnetic form factor ratio, G(E)/G(M), obtained separately from cross section and polarization transfer measurements. One possible explanation for this difference is a two-photon-exchange contribution. In an effort to search for effects beyond the one-photon-exchange or Born approximation, we report measurements of polarization transfer observables in the elastic H(e[over →],e(')p[over →]) reaction for three different beam energies at a Q(2)=2.5 GeV(2), spanning a wide range of the kinematic parameter ε. The ratio R, which equals μ(p)G(E)/G(M) in the Born approximation, is found to be independent of ε at the 1.5% level. The ε dependence of the longitudinal polarization transfer component P(ℓ) shows an enhancement of (2.3±0.6)% relative to the Born approximation at large ε.
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Affiliation(s)
- M Meziane
- The College of William and Mary, Williamsburg, Virginia 23187, USA.
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16
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Puckett AJR, Brash EJ, Jones MK, Luo W, Meziane M, Pentchev L, Perdrisat CF, Punjabi V, Wesselmann FR, Ahmidouch A, Albayrak I, Aniol KA, Arrington J, Asaturyan A, Baghdasaryan H, Benmokhtar F, Bertozzi W, Bimbot L, Bosted P, Boeglin W, Butuceanu C, Carter P, Chernenko S, Christy E, Commisso M, Cornejo JC, Covrig S, Danagoulian S, Daniel A, Davidenko A, Day D, Dhamija S, Dutta D, Ent R, Frullani S, Fenker H, Frlez E, Garibaldi F, Gaskell D, Gilad S, Gilman R, Goncharenko Y, Hafidi K, Hamilton D, Higinbotham DW, Hinton W, Horn T, Hu B, Huang J, Huber GM, Jensen E, Keppel C, Khandaker M, King P, Kirillov D, Kohl M, Kravtsov V, Kumbartzki G, Li Y, Mamyan V, Margaziotis DJ, Marsh A, Matulenko Y, Maxwell J, Mbianda G, Meekins D, Melnik Y, Miller J, Mkrtchyan A, Mkrtchyan H, Moffit B, Moreno O, Mulholland J, Narayan A, Nedev S, Piasetzky E, Pierce W, Piskunov NM, Prok Y, Ransome RD, Razin DS, Reimer P, Reinhold J, Rondon O, Shabestari M, Shahinyan A, Shestermanov K, Sirca S, Sitnik I, Smykov L, Smith G, Solovyev L, Solvignon P, Subedi R, Tomasi-Gustafsson E, Vasiliev A, Veilleux M, Wojtsekhowski BB, Wood S, Ye Z, Zanevsky Y, Zhang X, Zhang Y, Zheng X, Zhu L. Recoil polarization measurements of the proton electromagnetic form factor ratio to Q2 = 8.5 GeV2. PHYSICAL REVIEW LETTERS 2010; 104:242301. [PMID: 20873943 DOI: 10.1103/physrevlett.104.242301] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Indexed: 05/29/2023]
Abstract
Among the most 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; indeed, recent proton data have attracted intense theoretical interest. In this Letter, we report new measurements of the proton electromagnetic form factor ratio using the recoil polarization method, at momentum transfers Q2=5.2, 6.7, and 8.5 GeV2. By extending the range of Q2 for which G(E)(p) is accurately determined by more than 50%, these measurements will provide significant constraints on models of nucleon structure in the nonperturbative regime.
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Affiliation(s)
- A J R Puckett
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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17
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Kivel N, Vanderhaeghen M. Two-photon exchange in elastic electron-proton scattering: a QCD factorization approach. PHYSICAL REVIEW LETTERS 2009; 103:092004. [PMID: 19792790 DOI: 10.1103/physrevlett.103.092004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2009] [Indexed: 05/28/2023]
Abstract
We estimate the two-photon exchange contribution to elastic electron-proton scattering at large momentum transfer Q(2). It is shown that the leading two-photon exchange amplitude behaves as 1/Q(4), and can be expressed in a model independent way in terms of the leading twist nucleon distribution amplitudes. Using several models for the nucleon distribution amplitudes, we provide estimates for existing data and for ongoing experiments.
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Affiliation(s)
- Nikolai Kivel
- Institute für Theoretische Physik II, Ruhr-Universität Bochum, D-44780 Bochum, Germany
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18
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Crawford CB, Sindile A, Akdogan T, Alarcon R, Bertozzi W, Booth E, Botto T, Calarco J, Clasie B, Degrush A, Donnelly TW, Dow K, Dutta D, Farkhondeh M, Fatemi R, Filoti O, Franklin W, Gao H, Geis E, Gilad S, Haeberli W, Hasell D, Hersman W, Holtrop M, Karpius P, Kohl M, Kolster H, Lee T, Maschinot A, Matthews J, McIlhany K, Meitanis N, Milner RG, Redwine RP, Seely J, Shinozaki A, Sirca S, Six E, Smith T, Tonguc B, Tschalaer C, Tsentalovich E, Turchinetz W, van den Brand JFJ, van der Laan J, Wang F, Wise T, Xiao Y, Xu W, Zhang C, Zhou Z, Ziskin V, Zwart T. -Measurement of the proton's electric to magnetic form factor ratio from 1H(over -->)(e(over -->),e'p). PHYSICAL REVIEW LETTERS 2007; 98:052301. [PMID: 17358849 DOI: 10.1103/physrevlett.98.052301] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2006] [Indexed: 05/14/2023]
Abstract
We report the first precision measurement of the proton electric to magnetic form factor ratio from spin-dependent elastic scattering of longitudinally polarized electrons from a polarized hydrogen internal gas target. The measurement was performed at the MIT-Bates South Hall Ring over a range of four-momentum transfer squared Q2 from 0.15 to 0.65 (GeV/c)(2). Significantly improved results on the proton electric and magnetic form factors are obtained in combination with existing cross-section data on elastic electron-proton scattering in the same Q2 region.
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Affiliation(s)
- C B Crawford
- Laboratory for Nuclear Science and Bates Linear Accelerator Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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19
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Jenkovszky L. Duality, analyticity, andtdependence of generalized parton distributions. Int J Clin Exp Med 2006. [DOI: 10.1103/physrevd.74.114026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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20
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Kondratyuk S, Blunden PG, Melnitchouk W, Tjon JA. Delta resonance contribution to two-photon exchange in electron-proton scattering. PHYSICAL REVIEW LETTERS 2005; 95:172503. [PMID: 16383824 DOI: 10.1103/physrevlett.95.172503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2005] [Revised: 10/11/2005] [Indexed: 05/05/2023]
Abstract
We calculate the effects on the elastic electron-proton scattering cross section of the two-photon exchange contribution with an intermediate Delta resonance. The Delta two-photon exchange contribution is found to be smaller in magnitude than the previously evaluated nucleon contribution, with an opposite sign at backward scattering angles. The sum of the nucleon and Delta two-photon exchange corrections has an angular dependence compatible with both the polarization-transfer and the Rosenbluth methods of measuring the nucleon electromagnetic form factors.
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Affiliation(s)
- S Kondratyuk
- Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada
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21
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Maas FE, Aulenbacher K, Baunack S, Capozza L, Diefenbach J, Gläser B, Imai Y, Hammel T, von Harrach D, Kabuss EM, Kothe R, Lee JH, Sanchez-Lorente A, Schilling E, Schwaab D, Stephan G, Weber G, Weinrich C, Altarev I, Arvieux J, Elyakoubi M, Frascaria R, Kunne R, Morlet M, Ong S, Vandewiele J, Kowalski S, Suleiman R, Taylor S. Measurement of the transverse beam spin asymmetry in elastic electron-proton scattering and the inelastic contribution to the imaginary part of the two-photon exchange amplitude. PHYSICAL REVIEW LETTERS 2005; 94:082001. [PMID: 15783877 DOI: 10.1103/physrevlett.94.082001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2004] [Indexed: 05/24/2023]
Abstract
We report on a measurement of the asymmetry in the scattering of transversely polarized electrons off unpolarized protons, A( perpendicular), at two Q2 values of 0.106 and 0.230 (GeV/c)(2) and a scattering angle of 30 degrees <theta(e)<40 degrees . The measured transverse asymmetries are A( perpendicular)(Q(2)=0.106 (GeV/c)(2))=(-8.59+/-0.89(stat)+/-0.75(syst))x10(-6) and A( perpendicular)(Q(2)=0.230 (GeV/c)(2))=(-8.52+/-2.31(stat)+/-0.87(syst))x10(-6). The first errors denote the statistical error and the second the systematic uncertainties. From comparison with theoretical estimates of A( perpendicular) we conclude that piN-intermediate states give a substantial contribution to the imaginary part of the two-photon amplitude. There is no obvious reason why this should be different for the real part of the two-photon amplitude, which enters into the radiative corrections for the Rosenbluth separation measurements of the electric form factor of the proton.
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Affiliation(s)
- F E Maas
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, J.-J.-Becherweg 45, D-55099 Mainz, Germany.
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22
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Chen YC, Afanasev A, Brodsky SJ, Carlson CE, Vanderhaeghen M. Partonic calculation of the two-photon exchange contribution to elastic electron-proton scattering at large momentum transfer. PHYSICAL REVIEW LETTERS 2004; 93:122301. [PMID: 15447254 DOI: 10.1103/physrevlett.93.122301] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2004] [Indexed: 05/24/2023]
Abstract
We estimate the two-photon exchange contribution to elastic electron-proton scattering at large momentum transfer through the scattering off a parton in the proton. We relate the two-photon exchange amplitude to the generalized parton distributions which appear in hard exclusive processes. We find that when taking the polarization transfer determinations of the form factors as input, adding in the 2-photon correction does reproduce the Rosenbluth cross sections.
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Affiliation(s)
- Y-C Chen
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
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23
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Stoler P. Connection between the elastic GEp/GMp and P-->Delta form factors. PHYSICAL REVIEW LETTERS 2003; 91:172303. [PMID: 14611337 DOI: 10.1103/physrevlett.91.172303] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2003] [Indexed: 05/24/2023]
Abstract
It is suggested that the falloff in Q2 of the P-->Delta magnetic form factor G*M is related to the recently observed falloff of the elastic electric form factor G(Ep)/G(Mp). Calculation is carried out in the framework of a generalized parton distribution model whose parameters are determined by fitting the elastic form factors F(1p) and F(2p) and isospin symmetry. When applied to the P-->Delta transition with no additional parameters, the shape of G*M is found to exhibit the requisite falloff with Q2.
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Affiliation(s)
- Paul Stoler
- Physics Department, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
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24
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Blunden PG, Melnitchouk W, Tjon JA. Two-photon exchange and elastic electron-proton scattering. PHYSICAL REVIEW LETTERS 2003; 91:142304. [PMID: 14611520 DOI: 10.1103/physrevlett.91.142304] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2003] [Indexed: 05/24/2023]
Abstract
Two-photon exchange contributions to elastic electron-proton scattering cross sections are evaluated in a simple hadronic model including the finite size of the proton. The corrections are found to be small in magnitude, but with a strong angular dependence at fixed Q2. This is significant for the Rosenbluth technique for determining the ratio of the electric and magnetic form factors of the proton at high Q2, and partly reconciles the apparent discrepancy with the results of the polarization transfer technique.
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Affiliation(s)
- P G Blunden
- Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2
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25
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Guichon PAM, Vanderhaeghen M. How to reconcile the Rosenbluth and the polarization transfer methods in the measurement of the proton form factors. PHYSICAL REVIEW LETTERS 2003; 91:142303. [PMID: 14611519 DOI: 10.1103/physrevlett.91.142303] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2003] [Indexed: 05/24/2023]
Abstract
The apparent discrepancy between the Rosenbluth and the polarization transfer methods for the ratio of the electric to magnetic proton form factors can be explained by a two-photon exchange correction which does not destroy the linearity of the Rosenbluth plot. Though intrinsically small, of the order of a few percent of the cross section, this correction is accidentally amplified in the case of the Rosenbluth method.
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Affiliation(s)
- P A M Guichon
- SPhN/DAPNIA, CEA Saclay, F91191 Gif sur Yvette, France
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26
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Freund A, Radyushkin AV, Schäfer A, Weiss C. Exclusive annihilation pp-->gammagamma in a generalized Parton picture. PHYSICAL REVIEW LETTERS 2003; 90:092001. [PMID: 12689214 DOI: 10.1103/physrevlett.90.092001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2002] [Indexed: 05/24/2023]
Abstract
Exclusive proton-antiproton annihilation into two photons at large s ( approximately 10 GeV2) and /t/,/u/ approximately s can be described by a generalized parton picture analogous to the "soft mechanism" in wide-angle real Compton scattering. The two photons are emitted in the annihilation of a single fast quark and antiquark. The matrix element describing the transition of the pp system to a qq pair can be related to the timelike proton elastic form factors as well as to the quark/antiquark distributions measured in inclusive deep-inelastic scattering. The reaction could be studied with the proposed 1.5-15 GeV high-luminosity antiproton storage ring (HESR) at GSI.
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Affiliation(s)
- A Freund
- Institut für Theoretische Physik, Universität Regensburg, D-93053 Regensburg, Germany
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27
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Gayou O, Aniol KA, Averett T, Benmokhtar F, Bertozzi W, Bimbot L, Brash EJ, Calarco JR, Cavata C, Chai Z, Chang CC, Chang T, Chen JP, Chudakov E, De Leo R, Dieterich S, Endres R, Epstein MB, Escoffier S, Fissum KG, Fonvieille H, Frullani S, Gao J, Garibaldi F, Gilad S, Gilman R, Glamazdin A, Glashausser C, Gomez J, Gorbenko V, Hansen JO, Higinbotham DW, Huber GM, Iodice M, de Jager CW, Jiang X, Jones MK, Kelly JJ, Khandaker M, Kozlov A, Kramer KM, Kumbartzki G, LeRose JJ, Lhuillier D, Lindgren RA, Liyanage N, Lolos GJ, Margaziotis DJ, Marie F, Markowitz P, McCormick K, Michaels R, Milbrath BD, Nanda SK, Neyret D, Papandreou Z, Pentchev L, Perdrisat CF, Piskunov NM, Punjabi V, Pussieux T, Quéméner G, Ransome RD, Raue BA, Roché R, Rvachev M, Saha A, Salgado C, Sirca S, Sitnik I, Strauch S, Todor L, Tomasi-Gustafsson E, Urciuoli GM, Voskanyan H, Wijesooriya K, Wojtsekhowski BB, Zheng X, Zhu L. Measurement of G(E(p))/G(M(p)) in e(-->)p---> e(-->)p to Q(2) = 5.6 GeV(2). PHYSICAL REVIEW LETTERS 2002; 88:092301. [PMID: 11863996 DOI: 10.1103/physrevlett.88.092301] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2001] [Indexed: 05/23/2023]
Abstract
The ratio of the electric and magnetic form factors of the proton G(E(p))/G(M(p)), which is an image of its charge and magnetization distributions, was measured at the Thomas Jefferson National Accelerator Facility (JLab) using the recoil polarization technique. The ratio of the form factors is directly proportional to the ratio of the transverse to longitudinal components of the polarization of the recoil proton in the elastic e(-->)p---> e(-->)p reaction. The new data presented span the range 3.5< Q(2)< 5.6 GeV(2) and are well described by a linear Q(2) fit. Also, the ratio sqrt[Q(2)] F(2(p))/F(1(p)) reaches a constant value above Q(2) = 2 GeV(2).
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Affiliation(s)
- O Gayou
- College of William and Mary, Williamsburg, VA 23187, USA
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Vlahovic B, Voskanyan H, Wijesooriya K, Wojtsekhowski BB, Woo RJ, Xiong F, Zainea GD, Zhou Z. G(E(p))/G(M(p)) ratio by polarization transfer in e-->p --> ep-->. PHYSICAL REVIEW LETTERS 2000; 84:1398-1402. [PMID: 11017527 DOI: 10.1103/physrevlett.84.1398] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/1999] [Indexed: 05/23/2023]
Abstract
The ratio of the proton's elastic electromagnetic form factors, G(E(p))/G(M(p)), was obtained by measuring P(t) and P(l), the transverse and the longitudinal recoil proton polarization, respectively. For elastic e-->p-->ep-->, G(E(p))/G(M(p)) is proportional to P(t)/P(l). Simultaneous measurement of P(t) and P(l) in a polarimeter provides good control of the systematic uncertainty. The results for the ratio G(E(p))/G(M(p)) show a systematic decrease as Q2 increases from 0.5 to 3.5 GeV2, indicating for the first time a definite difference in the spatial distribution of charge and magnetization currents in the proton.
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Affiliation(s)
- B Vlahovic
- College of William and Mary, Williamsburg, Virginia 23187, USA
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Niculescu I, Keppel C, Liuti S, Niculescu G. Extraction of higher twists from electron-proton inclusive data at large Bjorkenx. Int J Clin Exp Med 1999. [DOI: 10.1103/physrevd.60.094001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Ilakovac A. Probing lepton-number and lepton-flavor violation in semileptonic tau decays into two mesons. PHYSICAL REVIEW. D, PARTICLES AND FIELDS 1996; 54:5653-5673. [PMID: 10021257 DOI: 10.1103/physrevd.54.5653] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Bijker R, Iachello F, Leviatan A. Electromagnetic form factors in a collective model of the nucleon. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1996; 54:1935-1953. [PMID: 9971543 DOI: 10.1103/physrevc.54.1935] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Belyaev VM, Radyushkin AV. Soft contribution to form factors of the gamma *p--> Delta + transition. PHYSICAL REVIEW. D, PARTICLES AND FIELDS 1996; 53:6509-6521. [PMID: 10019933 DOI: 10.1103/physrevd.53.6509] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Ilakovac A, Kniehl BA, Pilaftsis A. Semileptonic lepton-number- and/or lepton-flavor-violating tau decays in Majorana neutrino models. PHYSICAL REVIEW. D, PARTICLES AND FIELDS 1995; 52:3993-4005. [PMID: 10019626 DOI: 10.1103/physrevd.52.3993] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Bosted PE. Empirical fit to the nucleon electromagnetic form factors. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1995; 51:409-411. [PMID: 9970077 DOI: 10.1103/physrevc.51.409] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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