Three Illinois Physics faculty members receive Center for Advanced Study appointments

Illinois Physics Professors Sangjin Kim has been appointed a University of Illinois Center for Advanced Study (CAS) Fellow. Professors Anne Sickles and Benjamin Hooberman have been appointed CAS Associates. The three physicists are among 5 Fellows and 11 Associates in the 2022/23 cohort, selected for their potential to make significant contributions to their respective fields. CAS faculty are awarded release time from teaching and receive funding for large-scale initiatives that are collaborative and interdisciplinary. 

Sangjin Kim: Creating a Dynamic Map of the Cell

Illinois Physics Assistant Professor Sangjin Kim is an experimental biophysicist whose research lies in single-molecule imaging of biological systems. She uses physics-inspired methods and analyses to study complex biological processes such as gene expression, DNA supercoiling, and molecular diffusion inside living cells.

One big challenge within biology is the creation of detailed, large-scale pictures of the biomolecular contents of a cell. Common imaging techniques of biomolecules may yield high-resolution images of only a few kinds of molecules at a time. Given the huge molecular crowding within a cell, imaging only a few kinds of molecules does not provide full information about the molecular interactions that are important for biological processes. Generating a high-resolution, large-scale, dynamic picture of a cell’s internal proteins is an outstanding problem that Kim hopes to tackle.

Proteins may diffuse differently depending on their sizes or local cellular environments. Therefore, understanding a protein's diffusive behaviors provides clues to its biochemical surroundings and interactions with other biomolecules. Based on this idea, Kim intends to map out the diffusion dynamics of different proteins in a cell. To do so, she aims to tag and track proteins using super-resolution microscopy and develop computational algorithms that will classify the tagged proteins according to their cellular locations and diffusive states. 

“What we envision is a machine-learning-type analysis to cluster different proteins based on their locations and diffusive properties within a cell. It will be interesting to cluster different physical and chemical features of proteins and observe what kinds of features are important in diffusive behaviors in a given region of a cell,” Kim says.

Kim will initially implement her study in the model bacterium E. coli. In principle, there are up to 4,000 different types of proteins within a single E. coli bacterium, so a unique challenge will be to automate the algorithms to track each type of protein.

The CAS appointment will provide Kim time to work with her students to set up the groundwork for this project.

Kim received a bachelor’s degree in chemistry from Seoul National University and a doctoral degree in chemistry from Harvard University in 2010. She completed a postdoctoral researcher appointment at Yale University before joining the faculty at Illinois Physics in 2019.

Anne Sickles: Understanding the Fluidity of the Quark-Gluon Plasma

Illinois Physics Associate Professor Anne Sickles is an experimental nuclear physicist who studies the building blocks of atomic nuclei: quarks and gluons. Observing these particles, however, is difficult because the strong nuclear force tightly binds them in a state of confinement.

To study these particles, scientists collide nuclei together and free the confined quarks and gluons, forming a high-temperature, short-lived state of matter known as the quark-gluon plasma (QGP). After colliding, droplets of QGP cool down into normal matter and are then measured by detectors. QGPs form the hottest laboratory-made state of matter and have lifetimes on the order of 10^-22 seconds. In addition, QGPs exhibit near-perfect fluidity. The reason for this fluidity, however, is poorly understood.

Sickles notes, “The most basic question is why the QGP behaves like a fluid at all. Why, for example, is the QGP not an ideal gas?”

To answer these questions, Sickles will conduct experiments at Brookhaven National Laboratory’s Relativistic Heavy Ion Collider (RHIC), one of only two institutions in the world that produce the QGP (the other being CERN’s Large Hadron Collider). Sickles will lead a research team in commissioning a detector called sPHENIX, which is designed to measure high-energy bursts of quarks and gluons, known as “jets,” emitted by QGPs. In particular, Sickles and her team will be responsible for a sub-detector of sPHENIX known as the electromagnetic calorimeter, part of a calorimeter system that will measure a much wider energy range of jets than previous studies have done.

The CAS Fellowship will relieve Sickles of teaching duties and enable her to travel to the RHIC to participate in the calibration and testing of the sPHENIX detector as well as initial data collection.

Sickles obtained a bachelor’s degree in physics from Gonzaga University in 2001 and a doctoral degree in physics from Stony Brook University in 2005. She was as a postdoctoral researcher at Brookhaven National Lab from 2005 to 2009, before joining the scientific staff of Brookhaven in 2009 as a physicist. She joined the faculty at Illinois Physics in 2014.

Benjamin Hooberman: Searching for Supersymmetric Particles

Illinois Physics Associate Professor Benjamin Hooberman is an experimental particle physicist who studies physics beyond the standard model, a theoretical framework that summarizes our current understanding of elementary particles and their interactions.

As successful as the standard model is, it is well known that it does not give a complete picture of nature. For example, the standard model cannot explain certain phenomena such as the existence of dark matter. This and other shortcomings have prompted particle physicists to look for additional physics beyond the standard model.

One promising avenue to extend the standard model is supersymmetry, the idea that there exists a “superpartner” particle for each standard model particle.

Hooberman explains, “There are strong theoretical motivations for supersymmetric particles, but so far, there has been no direct experimental evidence.”

Hooberman will hunt for these particles at CERN’s Large Hadron Collider (LHC), at the  ATLAS detector, which detects particles emitted from high-energy proton-proton collisions. Supersymmetric particles may be among those particles emitted from such collisions. Most previous searches for supersymmetric particles at the ATLAS Experiment have been based on the assumption that these particles decay immediately after being produced. It is possible that supersymmetric particles may have evaded detection due to this assumption. Hooberman’s goal is to search for particles with longer lifetimes and make adjustments to the detector that enhance the sensitivity in future data.

Hooberman will also play an important role in leading the ATLAS Supersymmetry Group, an international team of roughly 300 scientists. He has recently been conferred the title of convener within the group. Hooberman will organize the activities of the group, evaluating the most recent results in supersymmetry and recommending new research directions and ideas.

The CAS appointment will relieve Hooberman of teaching duties and enable him to travel to CERN to lead the ATLAS Supersymmetry Group to make the necessary modifications to the ATLAS detector to enhance the sensitivity to long-lived supersymmetric particles.

Hooberman obtained a bachelor’s degree in physics from Columbia University in 2005. He received a doctoral degree in physics from the University of California, Berkeley in 2009 and and served as a postdoctoral research associate at Fermi National Accelerator Laboratory before joining the faculty at Illinois Physics in 2014.