From Gluon Topology to Quark Chirality: Novel Phenomena in Heavy Ion Collisions

Indiana University, Bloomington IN

Investigators

Abstract

Nuclear matter is at the heart of all visible matter in our universe. Its basic law has been identified as a quantum field theory (known as Quantum Chromodynamics or QCD) based on fundamental particles called quarks and gluons. Precisely how the various forms and properties of nuclear matter arise from these quarks and gluons remains one of the grand challenges in physics. This project will help address this challenge by studying nuclear matter under extreme conditions such as at super hot temperatures or in super strong magnetic fields, which are available via high energy collider experiments. The PI will study the topological component of QCD, characterize the properties of this component via collider experimental data, and seek direct evidence of its presence through a novel transport phenomenon called the Chiral Magnetic Effect. The PI will mentor students engaged in this research at both graduate and undergraduate levels. In addition the project will develop outreach activities that bring current research to K-12 students as well as the general public through a variety of local events and online platforms. The objective of this project is to investigate the non-perturbative dynamics of Quantum Chromodynamics (QCD) in its quark-gluon plasma (QGP) phase at extremely high temperatures, such as those produced in today's laboratory experiments at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC). The key approach is to study the properties of the gluon topological component as well as to search for its manifestation via novel transport phenomenon related to quark chirality. Three specific topics will be explored. The first is to develop a statistical ensemble model of the topological component and study how it can explain the QCD confinement transition and quantitatively describe relevant lattice QCD data. The second is to quantify the contributions to key transport properties of QGP from the topological component by systematical comparison with experimental data utilizing Beyesian inference methodology. The third is to investigate the manifestation of gluon topology via quark chirality fluctuations which could be experimentally probed through the Chiral Magnetic Effect and theoretically simulated by a state-of-the-art modeling framework developed by the PI's group. With all these combined, the project will help characterize the gluon topological component and provide a deep understanding of the QCD non-perturbative dynamics. 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.