Quantum entanglement in high-energy physics

Monday 20 May 2024, 14:30 → 18:00 Europe/Rome

Aula Conversi (Dipartimento di Fisica -ED.G.Marconi)

Giulia Negro (Purdue Univ.), Marco Fabbrichesi (Istituto Nazionale di Fisica Nucleare), Nello Bruscino (INFN & Sapienza Università)

In-depth afternoon of seminars on the measurement of quantum entanglement in high-energy physics

14:30 → 15:10 Quantum Entanglement and Bell inequality violation at colliders

The study of entanglement in particle physics has been gathering pace in the past few years. It is a new field that is providing important results about the possibility of detecting entanglement and testing Bell inequality at colliders for final states as diverse as top-quark or tau-lepton pairs, massive gauge bosons and vector mesons. After a general introduction, I will discuss in detail B-meson decays, for which the Bell inequality has already been violated, and indicate what are the processes most likely to see it next.

Speaker: Marco Fabbrichesi (Istituto Nazionale di Fisica Nucleare)

15:30 → 15:50 Entangled in Tops - How we turned ATLAS into the world’s largest quantum information experiment

Quantum information science is rapidly evolving, and high-energy physics is joining the exploration. This talk presents the ATLAS Collaboration's groundbreaking measurement of quantum entanglement in top quark pair production—the highest-energy measurement of entanglement ever achieved and the first involving fundamental fermions. Focusing on a phase-space region near the top quark pair invariant mass threshold, quantum entanglement is observed through angular correlations in leptonic top quark decays. This pioneering work opens new avenues for future measurements of quantum information phenomena in top quark systems and other LHC channels.

Speaker: Nello Bruscino (Istituto Nazionale di Fisica Nucleare)

Bruscino.ATLAS.QE.pdf

16:00 → 16:20 Entangled titans: unraveling the mysteries of quantum mechanics with top quarks at the CMS experiment

Entanglement is an intrinsic property of quantum mechanics and its measurement probes the current understanding of the underlying quantum nature of elementary particles. The measurement of the extent of quantum entanglement in a top quark-antiquark system performed with data collected by the CMS experiment is presented in this talk. Entanglement is probed with a variable derived from spin correlations between the leptonic decay products of the top quarks, measured in the top quark pair production threshold region. For the first time, a pseudo-scalar component of the top quark-antiquark bound state, called toponium, is included in the signal model, improving the description of this threshold region. The observation of top quark entanglement, in agreement with Standard Model predictions, represents an important step forward towards quantum tomography and coherence in top quark events.

Speaker: Giulia Negro (Purdue Univ.)

16:30 → 16:50 P2VV measurements at LHCb: from Quantum Entanglement perspective

The LHCb experiment is a dedicated flavor physics experiment at the LHC, specialized in high-precision measurements of time-dependent B-meson decays. In this talk I'll give a short introduction to the study of B -> VV decays at LHCb and discuss the implications of the recent measurements for the quantum entanglement, and finish with prospects for future measurements using the upgrade of the LHCb experiment, which is taking data in nominal conditions since this year.

Speaker: Sevda Esen (LPNHE Paris)

Talks-41.pdf