Advancing Our Understanding of Quark Matter Using Jet Observables at RHIC

About This Grant

This award supports research into the fundamental building blocks of matter by investigating a new state of matter known as the quark-gluon plasma (QGP), which filled the universe just microseconds after the Big Bang. The QGP can be creating in the laboratory by colliding atomic nuclei at nearly the speed of light, generating droplets that are so hot that the quarks and gluons, normally confined inside protons and neutrons, are briefly freed. The PI and her team will study this plasma using jets, which are narrow sprays of particles created when quarks or gluons are scattered in the initial collision with high energy. As these jets travel through the QGP, they lose energy in a way that reveals information about the medium, much like a CT scan can reveal the internal structure of the human body. Understanding the structure of the QGP will improve the field’s understanding of quantum chromodynamics (QCD), the theory describing the strong nuclear force. This award will also give opportunities for training students in nuclear physics, instrumentation, and data science. The PI and her graduate students will also apply modern tools such as artificial intelligence to improve techniques for subtracting background signals from jet measurements, which remains one of the greatest challenges of this class of measurements. To support hands-on learning, the PI will construct a small electronics test stand that can be used to understand how different detector components operate. This will allow undergraduate students at the PI’s institution or other local institutions to gain practical experience in experimental nuclear physics and develop the skills essential for future scientific careers. This award will allow the PI, her graduate students and postdoc to investigates how the QGP modifies high-energy jets, focusing on the temperature, density, and path-length dependence of jet quenching. They will use the STAR and sPHENIX detectors at RHIC to measure dijet momentum imbalance and jet azimuthal anisotropy (v2) across multiple collision systems, including p+p, Au+Au, Ru+Ru, Zr+Zr, and potentially O+O. Advanced analysis techniques such as Event Shape Engineering (ESE) and Jet Geometry Engineering (JGE) will be used to isolate the geometric dependence of jet energy loss and enhance the sensitivity of the jets to the spatial and dynamical structure of the QGP. The STAR and sPHENIX Event Plane Detectors (EPDs), which are essential for determining the collision geometry, were both designed, constructed, and maintained by the PI and her group. This provides a unique opportunity to cross-calibrate global event properties between the two experiments, reducing systematic uncertainties in RHIC jet measurements. Jets produced at RHIC energies interact with the QGP over longer timescales than those at the LHC, making them well-suited to probing medium-induced modifications, though they are also more vulnerable to background contamination. To address this, the PI and her group will apply AI-driven techniques to disentangle medium response and background contributions from the intrinsic, but modified, jet structure, improving the precision of both the dijet and v2 measurements. This award will also support continued calibration and data production efforts for the EPDs, contributing directly to the broader RHIC physics program. Together, these efforts aim to enable tomographic imaging of the QGP and establish essential methodologies for future jet studies at the Electron-Ion Collider. 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.