Measuring Recoiling Nucleons from the Nucleus with the Electron Ion Collider

Abstract

Short range correlated nucleon-nucleon (N N ) pairs are an important part of the nuclear ground state. They are typically studied by scattering an electron from one nucleon in the pair and detecting its spectator correlated partner ("spectator-nucleon tagging"). The Electron Ion Collider (EIC) should be able to detect these nucleons, since they are boosted to high momentum in the lab frame by the momentum of the ion beam. To determine the feasibility of these studies with the planned EIC detector configuration, we have simulated quasi-elastic scattering for two electron and ion beam energy configurations: 5 GeV e − and 41 GeV/A ions, and 10 GeV e − and 110 GeV/A ions. We show that the knocked-out and recoiling nucleons can be detected over a wide range of initial nucleon momenta. We also show that these measurements can achieve much larger momentum transfers than current fixed target experiments. By detecting both low and high initial-momentum nucleons, the EIC will provide the data that should allow scientists to definitively show if the EMC effect and short-range correlation are connected, and to improve our understanding of color transparency.1 before the interaction and momentum p 1 + q and energy 1 + ω after. The recoil partner nucleon is treated as an on-shell spectator and is emitted with momentum p 2 = p c.m. − p 1 and corresponding energy. p c.m. is the center of mass motion of the SRC pair. In the GCF

BeAGLE: Benchmark $e$A Generator for LEptoproduction in high energy lepton-nucleus collisions

“…In parallel to this work, there are recent efforts in improving the parton energy loss model PyQM in a different study [30], modification of the DIS kinematics in light nuclei to account for Fermi momentum, implementation of the EMC effect [56][57][58][59][60], and short-range correlations using a generalized-contact formalism [61][62][63] for lower energy scattering. All past studies, the current work, and future studies have positioned BeAGLE as the prime MC tool for studying lepton-nucleus collisions at high energy, particularly towards the upcoming EIC.…”

u-Channel Color Transparency Observables

“…Here, it is important to point out that the color transparency study has been proposed at the EIC through e + p and e + A scatterings, and photoproduction of mesons [29,31]. These CT studies are based on the validity of collinear factorization theme in the small −t kinematics, and should be distinguished from the u-channel meson electroproduction observable proposed in this paper.…”

Event Generators for High-Energy Physics Experiments

“…Medium-term, BeAGLE can be used as an afterburner to another primary model, e.g., Angantyr, to apply the nuclear breakup model to the spectator nucleons. A similar approach has already been used to study the physics of tagged Short-Range Correlations [1189]. The Generalized-Contact-Formalism (GCF) generator [1190] simulates the hard interaction between the electron and a pair of nucleons and leaves the rest to BeAGLE as is.…”