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Quark and Gluon Tomography of the Helium-4 Nucleus

V. Martínez-Fernández1,2, B. Pire3, P. Sznajder4, and J. Wagner4

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Phys. Rev. Lett. 137, 111905 – Published 9 September, 2026

DOI: https://doi.org/10.1103/634s-zcy6

Abstract

QCD collinear factorization allows coherent hard exclusive reactions to reveal the quark-gluon structure of light nuclei, enabling their 3D tomography. In this Letter, we investigate elastic form factors and deeply virtual Compton scattering on a helium-4 target. We achieve unprecedented theoretical precision for this type of analysis by constraining generalized parton distributions at next-to-leading order in αs, incorporating kinematic twist corrections, and utilizing full evolution equations. Ultimately, we present the first tomography of a light nucleus, revealing distinct transverse spatial distributions of quarks and gluons.

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Coherent deeply virtual Compton scattering on He4 beyond leading power

V. Martínez-Fernández, B. Pire, P. Sznajder, and J. Wagner
Phys. Rev. C 114, 035203 (2026)

Article Text

References (34)

  1. X.-D. Ji, Off forward parton distributions, J. Phys. G 24, 1181 (1998).
  2. M. Diehl, Generalized parton distributions in impact parameter space, Eur. Phys. J. C 25, 223 (2002); 31, 277(E) (2003).
  3. A. V. Belitsky and D. Müller, Probing generalized parton distributions with electroproduction of lepton pairs off the nucleon, Phys. Rev. D 68, 116005 (2003).
  4. E. R. Berger, F. Cano, M. Diehl, and B. Pire, Generalized parton distributions in the deuteron, Phys. Rev. Lett. 87, 142302 (2001).
  5. A. Kirchner and D. Mueller, Deeply virtual Compton scattering off nuclei, Eur. Phys. J. C 32, 347 (2003).
  6. V. Guzey and M. Strikman, DVCS on spinless nuclear targets in impulse approximation, Phys. Rev. C 68, 015204 (2003).
  7. F. Cano and B. Pire, Deep electroproduction of photons and mesons on the deuteron, Eur. Phys. J. A 19, 423 (2004).
  8. S. Scopetta, Generalized parton distributions of He3, Phys. Rev. C 70, 015205 (2004).
  9. J. P. Repellin, P. Lehmann, J. Lefrançois, and D. B. Isabelle, Elastic electron scattering on helium 4, Phys. Lett. 16, 169 (1965).
  10. R. F. Frosch, J. S. McCarthy, R. E. Rand, and M. R. Yearian, Structure of the He4 nucleus from elastic electron scattering, Phys. Rev. 160, 874 (1967).
  11. R. G. Arnold et al., Elastic electron scattering from He3 and He4 at high momentum transfer, Phys. Rev. Lett. 40, 1429 (1978).
  12. C. R. Ottermann, G. Kobschall, K. Maurer, K. Rohrich, C. Schmitt, and V. H. Walther, Elastic electron scattering from He3 and He4, Nucl. Phys. A436, 688 (1985).
  13. A. Camsonne et al. (Jefferson Lab Hall A Collaboration), JLab measurement of the He4 charge form factor at large momentum transfers, Phys. Rev. Lett. 112, 132503 (2014).
  14. M. Hattawy et al. (CLAS Collaboration), First exclusive measurement of deeply virtual Compton scattering off He4: Toward the 3D tomography of nuclei, Phys. Rev. Lett. 119, 202004 (2017).
  15. A. Bacchetta, U. D’Alesio, M. Diehl, and C. A. Miller, Single-spin asymmetries: The Trento conventions, Phys. Rev. D 70, 117504 (2004).
  16. R. Kleiss, The cross section for e+e−→e+e−e+e−, Nucl. Phys. B241, 61 (1984).
  17. R. Kleiss and W. Stirling, Spinor techniques for calculating pp→W±/Z0+jets, Nucl. Phys. B262, 235 (1985).
  18. V. Martínez-Fernández, B. Pire, P. Sznajder, and J. Wagner, companion paper, Coherent deeply virtual Compton scattering on He4 beyond leading power, Phys. Rev. C 114, 035203 (2026).
  19. X.-D. Ji and J. Osborne, One loop corrections and all order factorization in deeply virtual Compton scattering, Phys. Rev. D 58, 094018 (1998).
  20. V. M. Braun, A. N. Manashov, and B. Pirnay, Finite-t and target mass corrections to DVCS on a scalar target, Phys. Rev. D 86, 014003 (2012).
  21. H. Moutarde, B. Pire, F. Sabatie, L. Szymanowski, and J. Wagner, Timelike and spacelike deeply virtual Compton scattering at next-to-leading order, Phys. Rev. D 87, 054029 (2013).
  22. V. Martinez-Fernandez, B. Pire, P. Sznajder, and J. Wagner, Timelike Compton scattering on a spin-0 target with kinematic twist-4 precision, Phys. Rev. D 111, 074034 (2025).
  23. A. V. Radyushkin, Double distributions and evolution equations, Phys. Rev. D 59, 014030 (1999).
  24. M. V. Polyakov and C. Weiss, Skewed and double distributions in pion and nucleon, Phys. Rev. D 60, 114017 (1999).
  25. R. Abdul Khalek, R. Gauld, T. Giani, E. R. Nocera, T. R. Rabemananjara, and J. Rojo, nNNPDF3.0: Evidence for a modified partonic structure in heavy nuclei, Eur. Phys. J. C 82, 507 (2022).
  26. V. Bertone, APFEL++: A new PDF evolution library in C++, Proc. Sci. DIS2017 (2018) 201 [arXiv:1708.00911].
  27. B. Pire, J. Soffer, and O. Teryaev, Positivity constraints for off—forward parton distributions, Eur. Phys. J. C 8, 103 (1999).
  28. M. Kirch, P. V. Pobylitsa, and K. Goeke, Inequalities for nucleon generalized parton distributions with helicity flip, Phys. Rev. D 72, 054019 (2005).
  29. M. Burkardt, Impact parameter space interpretation for generalized parton distributions, Int. J. Mod. Phys. A 18, 173 (2003).
  30. S. V. Goloskokov and P. Kroll, The longitudinal cross-section of vector meson electroproduction, Eur. Phys. J. C 50, 829 (2007).
  31. P. J. Mohr, D. B. Newell, B. N. Taylor, and E. Tiesinga, CODATA recommended values of the fundamental physical constants: 2022, Rev. Mod. Phys. 97, 025002 (2025).
  32. R. Dupré et al. (CLAS Collaboration), Measurement of deeply virtual Compton scattering off He4 with the CEBAF Large Acceptance Spectrometer at Jefferson Lab, Phys. Rev. C 104, 025203 (2021).
  33. R. Abdul Khalek et al., Science requirements and detector concepts for the electron-ion collider: EIC yellow report, Nucl. Phys. A1026, 122447 (2022).
  34. D. P. Anderle et al., Electron-ion collider in China, Front. Phys. 16, 64701 (2021).

Outline

Information

Phys. Rev. Lett. 137, 111905– Published 9 September, 2026
  • Received 19 May 2026
  • Revised 15 July 2026
  • Accepted 20 August 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.

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