Quarkonium as Quantum Probe of the QGP in the Open Quantum System Framework

by Tom Magorsch (TU Munich), Tom Magorsch

Thursday 4 Jun 2026, 10:00 → 12:00 Europe/Zurich

4/2-037 - TH meeting room (CERN)

In this talk, I discuss heavy quarkonium as a quantum probe of the QGP within the open quantum system framework.
After briefly introducing the formalism, I demonstrate how higher-order terms in an expansion of the binding energy over the temperature enable thermalization of the bottomonium. Motivated by this, I show an extension of the formalism that avoids the $E/T$ expansion and briefly introduce a novel simulation framework to perform scalable calculations in this setting. Notably, without the $E/T$ expansion, bottomonium dynamics depend on the full chromoelectric spectral function instead of a finite set of transport coefficients characterizing the QGP.

Finally, I discuss the role of the quantum nature of bottomonium in its dynamics. By calculating the time evolution of the negativity in Wigner space, assess the evolution of quantum features and study their relevance to the survival probability of bottomonium. I show that the $\Upsilon(1S)$ is largely insensitive to the negative regions in the phase space, while the $\Upsilon(2S)$ and  $\Upsilon(3S)$ show a large sensitivity. Finally, I show that partial classicalization is driven by a conditional purification of the bottomonium ensemble, resulting from the dipole interaction predominantly dissolving weakly bound bottomonium modes.