Phenomenological assessment of proton mechanical properties from deeply virtual Compton scattering

H. Dutrieux (1) , C. Lorcé (2) , H. Moutarde (1) , P. Sznajder , A. Trawiński (1, 2) , J. Wagner

1 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers
2 CPHT - Centre de Physique Théorique [Palaiseau]

A unique feature of generalised parton distributions is their relation to the QCD energy–momentum tensor. In particular, they provide access to the mechanical properties of the proton i.e. the distributions of pressure and shear stress induced by its quark and gluon structure. In principle the pressure distribution can be experimentally determined in a model-independent way from a dispersive analysis of deeply virtual Compton scattering data through the measurement of the subtraction constant. In practice the kinematic coverage and accuracy of existing experimental data make this endeavour a challenge. Elaborating on recent global fits of deeply virtual Compton scattering measurements using artificial neural networks, our analysis presents the current knowledge on this subtraction constant and assesses the impact of the most frequent systematic assumptions made in this field of research. This study will pave the way for future works when more precise data will become available, e.g. obtained in the foreseen electron-ion colliders EIC and EIcC.

Mots clés: 3D Nucleon Structure; Nucleon Tomography; Global Fit; Deeply Virtual Compton Scattering; DVCS; Compton Form Factor; CFF; Dispersion Relation; Subtraction Constant; tensor: energy-momentum; electron nucleon: colliding beams; generalized parton distribution; deeply virtual Compton scattering; pressure; quantum chromodynamics; electron nucleus: colliding beams; neural network; dispersion relation; kinematics; structure; quark; gluon

Domaines: Physique des Hautes Energies - Phénoménologie [hep-ph]

H. Dutrieux, C. Lorcé, H. Moutarde, P. Sznajder, A. Trawiński, et al.. Phenomenological assessment of proton mechanical properties from deeply virtual Compton scattering. Eur.Phys.J.C, 2021, 81 (4), pp.300. ⟨10.1140/epjc/s10052-021-09069-w⟩. ⟨hal-03129424⟩