NPA Seminar, Laura Havener, Yale, “Exploring QCD with quarks, gluons, and the quark-gluon plasma”

The smallest building blocks of matter, quarks and gluons (partons), are usually confined inside protons and neutrons (hadrons). At very high energies and temperatures, the partons become deconfined or “free”, forming a novel state of matter called the Quark-Gluon plasma (QGP). The QGP is produced at high-energy colliders by smashing together heavy ions and is found to be a nearly perfect fluid, but precise knowledge of its intrinsic properties is required. Jets are ideal probes of the QGP. Jets are collimated streams of partons from high-momentum QCD scatterings that experience the full QGP evolution and interact with it, encoding information about its properties. Due to these interactions, the jets lose energy and their complex structure is modified, a phenomenon called jet quenching. The patterns within the jet structure contain information about fundamental QCD processes like confinement. Jet substructure observables were designed for proton-proton collisions to reveal these patterns. In heavy-ion collisions, they can isolate different jet-medium interactions and uncover a space-time picture of the QGP.
In this seminar, I will discuss novel methods and observables for experimentally measuring jets and jet substructure at the LHC in proton-proton and heavy-ion collisions and what they tell us about the QGP and fundamental QCD. Additionally, I will motivate future jet substructure measurements at the LHC using new ALICE data to study the microscopic structure of the QGP and the dynamics of confinement. Finally, I will introduce the next QCD frontier at the Electron-Ion Collider (EIC), where jets will play a crucial role in the physics program to study precision QCD.
Host: Nikhil Padmanabhan (nikhil.padmanabhan@yale.edu)