RUI: Nucleon Structure Studies via Electron Scattering at JLab 12 GeV

Christopher Newport University, Newport News VA

Investigators

Abstract

It has been established that protons and neutrons (nucleons) have a substructure made up of elementary constituent particles called quarks and gluons. Quantum Chromodynamics (QCD) is an established theory of how these constituents interact giving rise to the strong nuclear force and the fundamental properties of nucleons. The research program supported by this grant is aimed at improving the fundamental understanding of nucleon structure. This goal will be achieved through electron scattering experiments to be performed at the Thomas Jefferson National Accelerator Facility (JLab). These experiments will measure the spatial distributions of electric charge and current in both the proton and the neutron; this information is encoded in the nucleon electromagnetic form factors. A fundamental understanding of the nucleon form factors in terms of QCD is one of the outstanding challenges in nuclear physics today. Why and how do quarks forms colorless hadrons with only two stable configurations, the proton and neutron? One important step towards addressing this challenge is to characterize the internal structure of the nucleon via form factor measurements. The anticipated research activities will cover a range of both hardware and software projects. These projects will provide outstanding research opportunities for undergraduate students, furthering their education outside the classroom, preparing them for a career in science, technology, engineering and mathematics (STEM) and laying the foundations for successful graduate studies. The funding support for this research program will enable the PI and Christopher Newport University students to contribute to a number of projects at JLab, aimed at improving the fundamental understanding of nucleon structure. The proposed projects include an experimental effort - the Super Bigbite Spectrometer program (SBS) - and a phenomenology effort - CTEQ-JLab (CJ) - both of which address fundamental questions of hadronic structure in the QCD framework. The SBS program comprises high impact experiments studying the electromagnetic form factors of both the proton and neutron at a much higher momentum transfer than previously studied. The new data from the SBS experiments will allow a partonic flavor decomposition of the form factors to be performed, which in turn can be tested using calculations provided by the CJ effort. The PI is leading the commissioning effort of one of the SBS detector systems, as well as contributing to the analysis effort in the CJ project This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.