Speaker
Description
Understanding nucleon structure is important, as it is one of the building blocks of the visible universe. Usually, nucleon structure is studied using electromagnetic probes, such as electrons. At low-energy Quantum Chromo-Dynamics (QCD), the study is in a non-perturbative regime. This means that it is necessary to introduce structure functions to describe the nucleon's internal dynamics. Ones of those functions are Generalized Parton Distributions (GPDs). GPDs convey an image where the transverse position and the longitudinal momentum of the partons inside the nucleon are correlated. The golden channel for accessing GPDs is Deeply Virtual Compton Scattering (DVCS), the electroproduction of a photon from one of the partons inside the nucleon. When the nucleon is in a bound state within a nucleus, such as deuterium, the partonic structure can be modified by internal nucleon-nucleon correlations, known as short-range correlations (SRC). It is likely that SRCs could be related to the well-known EMC effect. One of the experimental observables that gives access to GPDs is the Beam Spin Asymmetry (BSA). Accessing these observables requires a polarized electron beam. The CLAS12 experiment at JLab provides a polarized electron beam of up to 12 GeV suitable for DVCS measurements. Here, we present results from the analysis of DVCS off-neutron in deuterium data and the preliminary extraction of BSA. In the context of nucleon structure studies, the future Electron-Ion Collider (EIC) will provide a valuable laboratory to probe GPDs at both the quark and gluon levels. To meet the physics requirements of the EIC, the ePIC detector is being developed. The Electron Endcap Electromagnetic Calorimeter (EEEMCal) of ePIC will be composed of 2722 lead-tungstate crystals, each coupled to 16 silicon photomultipliers, with a readout chain based on HGCROC ASICs developed for the CMS experiment at the LHC. The work presented here focuses on the commissioning and characterization of the electronic readout of a 25-crystal EEEMCal prototype. In particular, we developed an ASIC-by-ASIC calibration procedure, studied the reduction of electronic noise, and measured the energy resolution as a function of LED voltage. The performance obtained with the full readout chain is compared with reference measurements performed using an oscilloscope, providing a validation of the prototype readout and its suitability for future EEEMCal studies.