Abstract:
The Standard Model of particle physics is a quantum field theory, based on quantum mechanics and special relativity. Therefore, it allows us to test fundamental properties of quantum mechanics. Top-quark pairs, which are generated at the LHC, are a unique high-energy system since their spin correlations can be measured. Thus, it is possible to study fundamental aspects of quantum mechanics such as entanglement using top-quark pairs, represented as two qubits. The environment provided by the LHC makes these studies especially attractive: the qubits are genuinely relativistic, at energies which are many orders of magnitude above conventional condensed-matter and optical experiments. We will discuss the theoretical background and the first measurements of entanglement between top-quark pairs by the ATLAS and CMS collaborations.
Yoav Afik is an experimental physicist working with the ATLAS collaboration. He obtained his PhD at the Technion in Israel. He was then a research fellow at CERN, and currently he is a postdoctoral scholar at the Enrico Fermi Institute under the University of Chicago. He worked on a variety of topics, including dark matter searches, contact interactions and heavy resonances. His experimental analyses are typically following a theory paper which he participated in or even initiated. He was an author of the first paper which suggested to measure entanglement at the LHC, using top-quark pairs, of which the analyses discussed here are based on. In addition, he was a coordinator of the first measurement of entanglement in top-quark pairs by ATLAS.
Juan Antonio Aguilar Saavedera is a scientific researcher at CSIC (IFT/Madrid) and associate professor on leave from the University of Granada. He obtained his PhD at the University of Granada, moved to Instituto Superior Técnico of Lisbon as a post-doc, and returned to Granada for 15 years. He has worked on top quark physics, beyond-the-SM theories with vector-like quarks and leptons, effective field theory, jet tagging and anomaly detection, ambulance chasing, and in the last two years in quantum entanglement in high-energy physics.
Giulia Negro is an experimental physicist working in the CMS Collaboration. She obtained her PhD at CEA Paris-Saclay and she is currently a post-doctoral researcher at Purdue University. Her research work focuses on measurements of top quark polarizations and top quark-antiquark spin correlations and, more recently, on the entanglement between top quarks. She is also the former convener of the CMS Top Event Modelling and Generators group. In addition, she is deeply involved with the operations of the CMS detector being the deputy Run Coordinator and the Detector Performance Group Coordinator of the CMS experiment.