• Nuclear, Particle, Astroparticle and Cosmology (NUPAC) Seminars

August 25, 2026 2:00 PM
PAIS 3205

Host:

Huaiyu Duan

Presenter:

Preeti Dhankher Lesser (Nikhef)

The strong interaction, one of the four fundamental interactions governed by Quantum Chromodynamics (QCD), binds quarks and gluons (partons) into the visible matter of the universe. However, the exact mechanism of how partons bind together into specific hadrons, hadronization, is not fully understood. To investigate this mechanism, the hadron production is studied by colliding nuclei ranging from small to heavy at the Large Hadron Collider (LHC). In the large nuclear collisions, a deconfined state of quarks and gluons is formed: the quark-gluon plasma (QGP), which further complicates the hadronization by melting and reforming hadrons. Strikingly, an enhanced baryon (three-quark hadron) to meson (two-quark hadron) ratio--typically attributed to the enhanced binding of densely populated partons in the QGP--has unexpectedly been observed in small nuclear collisions as well, challenging our understanding of both vacuum and medium behavior. Beyond solving this puzzle, characterizing fundamental properties of the QGP, such as its transport properties, remains a primary goal of high-energy nuclear physics.

In this talk, I will explore how QCD manifests in collisions between both small and large nuclei, focusing on hadronization. Using heavy-flavor hadrons and jets as probes to elucidate the properties of the QGP medium, I will discuss key insights gained from recent measurements and highlight open questions that persist in our understanding of hadronization and QCD at extreme energy densities. Addressing these core challenges requires innovative experimental approaches, and I will outline the upcoming opportunities available at the LHC.

About the speaker

Preeti Dhankher Lesser is a postdoctoral fellow in experimental nuclear physics at Nikhef in Amsterdam, Netherlands. Her research focuses on understanding Quantum Chromodynamics at high energy densities through studies of heavy-flavor production and jet substructure with the ALICE experiment at CERN’s Large Hadron Collider. She has also contributed to the commissioning of the ALICE Inner Tracking System, a state-of-the-art silicon pixel detector for precision tracking and vertex reconstruction. Prior to joining Nikhef, she was a postdoctoral fellow at the University of California, Berkeley, where she led efforts on heavy-flavor jet substructure studies. She received her Ph.D. from the Indian Institute of Technology Bombay, where she studied heavy-flavor hadron production and worked on the fabrication and characterization of silicon pixel detectors.