Few-Body Systems

, 59:46 | Cite as

Nucleon Resonance Structure from Exclusive Meson Electroproduction with CLAS

Article
  • 6 Downloads
Part of the following topical collections:
  1. NSTAR 2017

Abstract

Studies of the nucleon resonance electroexcitation amplitudes in a wide range of photon virtualities offer unique information on many facets of strong QCD behind the generation of all prominent excited nucleon states of distinctively different structure. Advances in the evaluation of resonance electroexcitation amplitudes from the data measured with the CLAS detector and the future extension of these studies with the CLAS12 detector at Jefferson Lab are presented. For the first time, analyses of \(\pi ^0p\), \(\pi ^+n\), \(\eta p\), and \(\pi ^+\pi ^-p\) electroproduction off proton channels have provided electroexcitation amplitudes of most resonances in the mass range up to 1.8 GeV and at photon virtualities \(Q^2 < 5\) GeV\(^2\). Consistent results on resonance electroexcitation amplitudes determined from different exclusive channels validate a credible extraction of these fundamental quantities. Studies of the resonance electroexcitation amplitudes revealed the \(N^*\) structure as a complex interplay between the inner core of three dressed quarks and the external meson–baryon cloud. The successful description of the \(\varDelta (1232)3/2^+\) and \(N(1440)1/2^+\) electrocouplings achieved within the Dyson–Schwinger Equation approach under a traceable connection to the QCD Lagrangian and supported by the novel light front quark model demonstrated the relevance of dressed quarks with dynamically generated masses as an active structural component in baryons. Future experiments with the CLAS12 detector will offer insight into the structure of all prominent resonances at the highest photon virtualities, \(Q^2 < 12\) GeV\(^2\), ever achieved in exclusive reactions, thus addressing the most challenging problems of the Standard Model on the nature of hadron mass, quark–gluon confinement, and the emergence of nucleon resonance structures from QCD. A search for new states of hadronic matter, the so-called hybrid-baryons with glue as a structural component, will complete the long term efforts on the resonance spectrum exploration.

References

  1. 1.
    D. Binosi et al., Phys. Rev. D 96, 054026 (2017)ADSCrossRefGoogle Scholar
  2. 2.
    V.D. Burkert, The 11th International Workshop on the Physics of Excited Nucleons - N*2017. See these proceedings (2017)Google Scholar
  3. 3.
    C.D. Roberts, The 11th International Workshop on the Physics of Excited Nucleons - N*2017. See these proceedings (2017)Google Scholar
  4. 4.
    I.G. Aznauryan, V.D. Burkert, Prog. Part. Nucl. Phys. 67, 1 (2012)ADSCrossRefGoogle Scholar
  5. 5.
    V.D. Burkert, C.D. Roberts, arXiv:1710.02549 [nucl-ex] (2017)
  6. 6.
    I.G. Aznauryan, Phys. Rev. C 76, 025212 (2007)ADSCrossRefGoogle Scholar
  7. 7.
    I.G. Aznauryan, V.D. Burkert, Phys. Rev. C 85, 055202 (2012)ADSCrossRefGoogle Scholar
  8. 8.
    I.G. Aznauryan, V.D. Burkert, Phys. Rev. C 95, 065207 (2017)ADSCrossRefGoogle Scholar
  9. 9.
    I.T. Obukhovsky et al., Phys. Rev. D 84, 014004 (2011)ADSCrossRefGoogle Scholar
  10. 10.
    T. Gutsche, V.E. Lyubovitskij, I. Schmidt arXiv:1712.08410 [hep-ph] (2017)
  11. 11.
    M.M. Giannini, E. Santopinto, Chin. J. Phys. 53, 020301 (2015)Google Scholar
  12. 12.
    N. Suzuki, T. Sato, T.-S.H. Lee, Phys. Rev. C 82, 045206 (2010)ADSCrossRefGoogle Scholar
  13. 13.
    V.M. Braun et al., Phys. Rev. D 89, 094511 (2014)ADSCrossRefGoogle Scholar
  14. 14.
    I.V. Anikin et al., Phys. Rev. D 92, 014018 (2015)ADSCrossRefGoogle Scholar
  15. 15.
    C. Mezrag et al., arXiv:1711.09101 [nucl-th] (2017)
  16. 16.
    I. Aznauryan et al., Phys. Rev. C 80, 055203 (2009)ADSCrossRefGoogle Scholar
  17. 17.
    C.D. Roberts, Few Body Syst. 58, 5 (2017)ADSCrossRefGoogle Scholar
  18. 18.
    J. Segovia et al., Few Body Syst. 55, 1185 (2015)ADSCrossRefGoogle Scholar
  19. 19.
    J. Segovia et al., Phys. Rev. Lett. 115, 171801 (2015)ADSCrossRefGoogle Scholar
  20. 20.
    D. Binosi et al., Phys. Rev. D 95, 031501 (2017)ADSCrossRefGoogle Scholar
  21. 21.
    C. Chen et al., arXiv:1711.03142 [nucl-th] (2017)
  22. 22.
    C.D. Roberts, J. Phys. Conf. Ser. 706, 022003 (2016)CrossRefGoogle Scholar
  23. 23.
  24. 24.
    CLAS physics database. http://clasweb.jlab.org/physicsdb
  25. 25.
    H. Kamano, The 11th International Workshop on the Physics of Excited Nucleons - N* 2017. See these proceedings (2017)Google Scholar
  26. 26.
    K. Park et al., (CLAS Collaboration), Phys. Rev. C 91, 045203 (2015)Google Scholar
  27. 27.
    I.G. Aznauryan, Phys. Rev. C 68, 065204 (2003)ADSCrossRefGoogle Scholar
  28. 28.
    M. Ripani et al., (CLAS Collaboration), Phys. Rev. Lett. 91, 022002 (2003)Google Scholar
  29. 29.
    G.V. Fedotov et al., (CLAS Collaboration), Phys. Rev. C 79, 014204 (2009)Google Scholar
  30. 30.
    E.L. Isupov et al., (CLAS Collaboration), Phys. Rev. C 96, 025209 (2017)Google Scholar
  31. 31.
    V.I. Mokeev et al., Phys. Rev. C 80, 045212 (2009)ADSCrossRefGoogle Scholar
  32. 32.
    V.I. Mokeev et al., (CLAS Collaboration), Phys. Rev. C 86, 055203 (2012)Google Scholar
  33. 33.
    V.I. Mokeev et al., Phys. Rev. C 93, 025206 (2016)ADSCrossRefGoogle Scholar
  34. 34.
    Nucleon Resonance Photo-/Electrocouplings Determined from Analyses of Experimental Data on Exclusive Meson Electroproduction off Protons. https://userweb.jlab.org/~mokeev/resonance_electrocouplings/
  35. 35.
    Fit of the Resonance Electrocouplings. https://userweb.jlab.org/~isupov/couplings/
  36. 36.
    C. Patrignani et al., (Particle Data Group), Chin. Phys. C 40(10), 100001 (2016)Google Scholar
  37. 37.
    M. Dugger et al., (CLAS Collaboration), Phys. Rev. C 79, 065206 (2009)Google Scholar
  38. 38.
    A.V. Anisovich et al., Eur. Phys. J. A 48, 15 (2012)ADSCrossRefGoogle Scholar
  39. 39.
    A.V. Anisovich et al., Eur. Phys. J. A 50, 129 (2014)ADSCrossRefGoogle Scholar
  40. 40.
    D.S. Carman, The 11th International Workshop on the Physics of Excited Nucleons - N*2017. See these proceedings (2017)Google Scholar
  41. 41.
    B. Julia-Diaz et al., Phys. Rev. C 77, 045205 (2008)ADSCrossRefGoogle Scholar
  42. 42.
    E. Santopinto, M.M. Giannini, Phys. Rev. C 86, 065202 (2012)ADSCrossRefGoogle Scholar
  43. 43.
  44. 44.
    I.G. Aznauryan et al., Int. J. Mod. Phys. E 22, 1330015 (2013)ADSCrossRefGoogle Scholar
  45. 45.
    A. D’Angelo, V.D. Burkert, D.S. Carman, E. Golovatch, R. Gothe, V. Mokeev, A Search for Hybrid Baryons in Hall B with CLAS12, JLab Experiment E12-09-003Google Scholar
  46. 46.
    J.J. Dudek, R.G. Edwards, Phys. Rev. D 85, 054016 (2012)ADSCrossRefGoogle Scholar
  47. 47.
    V. Mathieu, G. Fox, A.P. Szczepaniak, Phys. Rev. D 92, 074013 (2015)ADSCrossRefGoogle Scholar
  48. 48.
    I. Strakovsky et al., EPJ Web Conf. 73, 04003 (2014)CrossRefGoogle Scholar
  49. 49.
    H. Kamano, S.X. Nakamura, T.-S.H. Lee, Phys. Rev. C 88, 035209 (2013)ADSCrossRefGoogle Scholar
  50. 50.
    V.D. Burkert, P. Cole, R. Gothe, K. Joo, V. Mokeev, P. Stoler, Nucleon Resonance Studies with CLAS12, JLab Experiment E12-09-003Google Scholar
  51. 51.
    D.S. Carman, R. Gothe, V. Mokeev, Exclusive \(N^* \rightarrow KY\) Studies with CLAS12, JLab Experiment E12-06-108AGoogle Scholar
  52. 52.
    D.S. Carman, R. Gothe, V. Mokeev, Nucleon Resonance Structure Studies Via Exclusive \(KY\) Electroproduction at 6.6 GeV and 8.8 GeV, JLab Experiment E12-16-010AGoogle Scholar
  53. 53.
    R. Briceno, The 11th International Workshop on the Physics of Excited Nucleons - N*2017. See these proceedings (2017)Google Scholar
  54. 54.
    N. Isgur, in Why N\(^*\) are important, ed. by V.D. Burkert, L. Elouadrhiri, J.J. Kelly, R.C. Minehart, Proceedings of the NSTAR2000 Conference, 16–19 Feb 2000, Newport News, USA, vol 403 (World Scientific, 2001)Google Scholar

Copyright information

© Springer-Verlag GmbH Austria, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Jefferson LaboratoryNewport NewsUSA

Personalised recommendations