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The European Physical Journal A

, Volume 37, Issue 1, pp 1–8 | Cite as

A new measurement of the structure functions PLL - PTT/ε and PLT in virtual Compton scattering at Q2 = 0.33 (GeV/c)2

  • P. Janssens
  • L. Doria
  • P. Achenbach
  • C. Ayerbe Gayoso
  • D. Baumann
  • J. C. Bernauer
  • I. K. Bensafa
  • R. Böhm
  • D. Bosnar
  • E. Burtin
  • N. D’Hose
  • X. Defaÿ
  • M. Ding
  • M. O. Distler
  • H. Fonvieille
  • J. Friedrich
  • J. M. Friedrich
  • G. Laveissière
  • M. Makek
  • J. Marroncle
  • H. Merkel
  • U. Müller
  • L. Nungesser
  • B. Pasquini
  • J. Pochodzalla
  • O. Postavaru
  • M. Potokar
  • D. Ryckbosch
  • S. Sanchez Majos
  • B. S. Schlimme
  • M. Seimetz
  • S. Širca
  • G. Tamas
  • R. Van de Vyver
  • L. Van Hoorebeke
  • A. Van Overloop
  • Th. Walcher
  • M. Weinriefer
Regular Article — Experimental Physics

Abstract

The cross-section of the epe′p′γ reaction has been measured at Q 2 = 0.33 (GeV/c)2. The experiment was performed using the electron beam of the MAMI accelerator and the standard detector setup of the A1 Collaboration. The cross-section is analyzed using the low-energy theorem for virtual Compton scattering, yielding a new determination of the two structure functions PLL - PTT/ε and PLT which are linear combinations of the generalized polarizabilities of the proton. We find somewhat larger values than in the previous investigation at the same Q 2. This difference, however, is purely due to our more refined analysis of the data. The results tend to confirm the non-trivial Q 2-evolution of the generalized polarizabilities and call for more measurements in the low-Q 2 region (≤ 1 (GeV/c)2).

PACS

13.60.Fz Elastic and Compton scattering 14.20.Dh Protons and neutrons 25.30.Rw Electroproduction reactions 

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Copyright information

© SIF, Springer-Verlag Berlin Heidelberg 2008

Authors and Affiliations

  • P. Janssens
    • 1
  • L. Doria
    • 2
  • P. Achenbach
    • 2
  • C. Ayerbe Gayoso
    • 2
  • D. Baumann
    • 2
  • J. C. Bernauer
    • 2
  • I. K. Bensafa
    • 3
  • R. Böhm
    • 2
  • D. Bosnar
    • 4
  • E. Burtin
    • 5
  • N. D’Hose
    • 5
  • X. Defaÿ
    • 3
  • M. Ding
    • 2
  • M. O. Distler
    • 2
  • H. Fonvieille
    • 3
  • J. Friedrich
    • 2
  • J. M. Friedrich
    • 6
  • G. Laveissière
    • 3
  • M. Makek
    • 4
  • J. Marroncle
    • 5
  • H. Merkel
    • 2
  • U. Müller
    • 2
  • L. Nungesser
    • 2
  • B. Pasquini
    • 7
  • J. Pochodzalla
    • 2
  • O. Postavaru
    • 10
  • M. Potokar
    • 8
  • D. Ryckbosch
    • 1
  • S. Sanchez Majos
    • 2
  • B. S. Schlimme
    • 2
  • M. Seimetz
    • 5
  • S. Širca
    • 8
    • 9
  • G. Tamas
    • 2
  • R. Van de Vyver
    • 1
  • L. Van Hoorebeke
    • 1
  • A. Van Overloop
    • 1
  • Th. Walcher
    • 2
  • M. Weinriefer
    • 2
  1. 1.Department of Subatomic and Radiation PhysicsUniversity of GentGentBelgium
  2. 2.Institut für KernphysikJohannes Gutenberg-UniversitätMainzGermany
  3. 3.LPC, Universitée Blaise Pascal, IN2P3Aubière CedexFrance
  4. 4.Department of PhysicsUniversity of ZagrebZagrebCroatia
  5. 5.CEA DAPNIA-SPhN, C.E. SaclayGif-sur-Yvette CedexFrance
  6. 6.Physik-DepartmentTechnische Universität MünchenGarchingGermany
  7. 7.Dipartimento di Fisica Nucleare e TeoricaUniversità degli Studi di Pavia, and INFN, Sezione di PaviaPaviaItaly
  8. 8.Jožef Stefan InstituteLjubljanaSlovenia
  9. 9.Department of PhysicsUniversity of LjubljanaLjubljanaSlovenia
  10. 10.Institute of Space ScienceBucharest-MagureleRomania

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