Experimental Nuclear Physics

The UCLA Nuclear Physics Group conducts cutting-edge experimental research to explore the properties of nuclear matter under extreme conditions and to probe the fundamental nature of neutrinos. Our research spans studies of hot Quantum Chromodynamics (QCD) matter, precision measurements of proton and nuclear structure, and searches for neutrinoless double-beta decay. These efforts involve major international collaborations at leading facilities, including the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL), the Gran Sasso National Laboratory in Italy, and the future Electron-Ion Collider (EIC).

At RHIC, we are founding members of the STAR and sPHENIX collaborations, where heavy-ion collisions recreate the quark-gluon plasma, a primordial state of matter that existed microseconds after the Big Bang. Our group investigates the QGP’s thermal behavior, collective dynamics, and phase transitions, as well as novel phenomena such as the chiral magnetic effect. We also contribute to detector development, including calorimetry upgrades, enabling precision measurements of these extreme states.

Our group is also integral to the design and development of the EIC, a revolutionary facility at Brookhaven National Laboratory. The EIC will provide unparalleled insights into the internal structure of protons and nuclei, enabling detailed studies of the role of quarks and gluons in mass, spin, and spatial distributions. We are contributing to the design and construction of hadronic calorimeters, which are essential for accurately measuring hadron energy and momentum in EIC experiments.

In addition, we are actively engaged in the CUORE experiment at Gran Sasso, which searches for neutrinoless double-beta decay—a rare process that could reveal whether neutrinos are Majorana particles. Such a discovery would revolutionize our understanding of the neutrino mass scale and its role in the matter-antimatter asymmetry of the universe. Our contributions include data analysis, detector calibration, and interpretation of experimental results, pushing CUORE to new levels of sensitivity.

Through these experimental efforts, we are advancing our understanding of nuclear matter and fundamental particles, making significant contributions to uncovering the properties of the strong interaction and the role of neutrinos in shaping the universe.

For inquiries, please contact: Prof. Huan Huang.

QCD and Nuclear Theory

The UCLA Nuclear Physics Group conducts cutting-edge theoretical research at the forefront of Quantum Chromodynamics (QCD) and nuclear theory, addressing fundamental questions about the behavior of quarks and gluons and their role in nuclear matter. Our work utilizes modern QCD tools, such as Soft Collinear Effective Theory (SCET) and QCD factorization, to provide essential insights and predictions that complement experimental efforts at RHIC, Jefferson Lab, the Large Hadron Collider (LHC), and the upcoming Electron-Ion Collider (EIC).

In hadron physics, we develop theoretical frameworks for three-dimensional imaging of protons and nuclei, capturing their internal momentum, spatial, and spin structures. Using QCD factorization techniques, we derive precise predictions for processes that probe these structures, enabling future EIC experiments to shed light on the contributions of gluons to the mass, spin, and dynamics of nuclear matter.

In collider physics, we focus on jets, jet substructure, and heavy flavor production in high-energy collisions. Leveraging SCET and QCD factorization, we explore novel observables such as energy-energy correlators, which provide a deeper understanding of the transition from quarks and gluons to hadrons. These tools allow us to probe the intricate dynamics of QCD with unprecedented precision, enhancing our understanding of particle production mechanisms.

In heavy-ion physics, we study the propagation, scattering, and energy loss of partons in the quark-gluon plasma (QGP), a state of matter that existed microseconds after the Big Bang. By applying SCET in the hot and dense medium, we explore the transport properties of QCD matter and its phase transitions, offering valuable theoretical guidance for experiments aimed at characterizing the QGP.

Our group also embraces emerging approaches, such as quantum simulations and machine learning, to tackle challenging problems in QCD. Quantum computing offers a novel pathway to address real-time dynamics and non-perturbative aspects of QCD, while machine learning enhances numerical simulations, accelerates data analysis, and aids in the development of innovative observables for precision studies.

By integrating modern QCD tools, advanced computational techniques, and close connections to experiments, our research bridges theory and observation, driving progress in our understanding of the strong interaction and the nature of nuclear matter. For more information, visit our research group website.

For inquiries, please contact: Prof. Zhongbo Kang.