Probing short-range nucleon-nucleon interactions with an electron-ion collider

Abstract

We derive the cross-section for exclusive vector meson production in high energy deeply inelastic scattering off a deuteron target that disintegrates into a proton and a neutron carrying large relative momentum in the final state. This cross-section can be expressed in terms of a novel gluon Transition Generalized Parton Distribution (T-GPD); the hard scale in the final state makes the T-GPD sensitive to the short distance nucleon-nucleon interaction. We perform a toy model computation of this process in a perturbative framework and discuss the time scales that allow the separation of initial and final state dynamics in the T-GPD. We outline the more general computation based on the factorization suggested by the toy computation: in particular, we discuss the relative role of "point-like" and "geometric" Fock configurations that control the parton dynamics of short range nucleon-nucleon scattering. With the aid of exclusive J/Ψ production data at HERA, as well as elastic nucleon-nucleon cross-sections, we estimate rates for exclusive deuteron photo-disintegration at a future Electron-Ion Collider (EIC). Our results, obtained using conservative estimates of EIC integrated luminosities, suggest that center-of-mass energies s N N ∼ 12 GeV 2 of the neutron-proton subsystem can be accessed. We argue that the high energies of the EIC can address outstanding dynamical questions regarding the short-range quark-gluon structure of nuclear forces by providing clean gluon probes of such "knockout" exclusive reactions in light and heavy nuclei. *

Review of the electric dipole moment of light nuclei

“…The Weinberg operator can be probed through the isoscalar contact CP-odd nucleon-nucleon interaction, but the calculation of this process suffers from a large uncertainty in the nuclear level calculation, due to the lack of informations of the nuclear force at short distance. This problem may be resolved if the short range behavior of the CP-even nuclear force is determined in high energy experiments, 224,225 or by lattice QCD calculations. 226,227 There are also no available results for the QCD calculation of the Weinberg operator contribution to the contact CP-odd nucleon-nucleon interaction.…”

Mining for Gluon Saturation at Colliders

“…Incoherent production is also interesting as one expects sensitivity to subnucleonic fluctuations of various kinds. At the EIC, in addition to incoherent events in heavy nucleus DIS, we will also be able to study DIS off light-nuclei and study the interplay of short range correlations and gluon saturation [194][195][196].…”

Mining for Gluon Saturation at Colliders

“…Incoherent production is also interesting as one expects sensitivity to subnucleonic fluctuations of various kinds. At the EIC, in addition to incoherent events in heavy nucleus DIS, we will also be able to study DIS off light-nuclei and study the interplay of short range correlations and gluon saturation [195][196][197].…”