CAREER: Hadron's Transverse Structure and Associated QCD Dynamics

University Of California-Los Angeles, Los Angeles CA

Investigators

Abstract

Nucleons (protons and neutrons) are the building blocks of matter, and also known to be the bound states of quarks and gluons - the elementary particles that give rise to most of the mass in the visible universe. Quantum Chromodynamics (QCD) is the microscopic theory of strong interactions - one of the four fundamental forces - which describes how quarks and gluons interact with each other. The fundamental laws of QCD are elegantly concise; however, understanding the structural complexity of protons and neutrons in terms of quarks and gluons governed by those laws is one of the most important challenges facing physics today, a challenge that motivates the newest generation of experimental facilities, supercomputers, and nuclear scientists. The goal of this project is to perform new theoretical analysis and computations for important QCD scattering processes, develop phenomenological tools that can be used for reliable extraction of quark and gluon structure of the nucleon from existing and future experimental measurements, and thus address outstanding questions related to hadron structure and associated QCD dynamics. For example, the fundamental questions that the project will be able to address include: what role does the confined motion of quarks and gluons inside the nucleons play? Are there quantum correlations between the motion of quarks and gluons, their spin and the spin of the nucleon? How do quarks and gluons that come out of a high energy scattering make a transition into hadrons? What new insights can be gained from the production of collimated spray of hadrons (so-called jets)? This project will also provide much-needed guidance and predictions for the future Electron Ion Collider, the flagship nuclear experimental facility planned in the nuclear physics community. 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.