Microscopic Properties of Hot and Dense QCD Matter

点击翻译按钮获取中文摘要

A few micro-seconds into the cooling process of the early Universe, an extremely hot plasma of elementary particles (quarks and gluons) condensed into bound states called hadrons, the building blocks of the visible matter in the Universe. The condensation of the quark-gluon plasma (QGP) confined the quarks and gluons into hadrons and generated about 98% of the visible mass. The discovery of the mechanisms of quark confinement and hadron mass generation are central goals of fundamental research in particle and nuclear physics. Experimentally, small droplets of QGP, at record temperatures exceeding 2 trillion Kelvin, can be re-created in the laboratory by colliding atomic nuclei at high energies, at the Relativistic Heavy-Ion Collider and the Large Hadron Collider. However, it is very challenging to infer the properties of the QGP and its hadronization from the measured particle spectra. The PI, together with his graduate students and collaborators, will develop theoretical methods and apply them to unravel fundamental properties of the QGP from experimental data. His research and educational activities also encompass undergraduate research and outreach to high-school students within the Saturday Morning Physics program at Texas A&M. The heavy charm and bottom quarks, as well as electromagnetic (EM) radiation, are particularly valuable probes of the QGP. The PI will use state-of-the-art quantum many-body theory of the strong nuclear force to analyze the diffusion of heavy quarks (Brownian motion) and their subsequent hadronization. A systematic analysis of the experimental spectra of baryons (3-quark states) and mesons (quark-antiquark states) containing heavy quarks will unravel mechanisms of hadronization and provide unprecedented precision in the extraction of the heavy-quark diffusion coefficient, a key quantity to characterize the interaction strength in the QGP. The PI will further use EM radiation, which can penetrate the QGP formed in heavy-ion collisions, to analyze the mechanism of mass generation. He will investigate the spectral modifications of baryons near the hadronization transition and extract the electric conductivity, another fundamental transport parameter of the medium.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.