Nonlocal Advantage of Quantum Coherence in Top Quarks

TL;DR

This paper explores the nonlocal advantage of quantum coherence in top quark pairs, revealing new quantum signatures that could enhance understanding of fundamental physics beyond current models.

Contribution

It is the first detailed study of NAQC in top quark systems, employing two measures and analyzing angular effects to uncover novel quantum coherence features.

Findings

Revealed rich coherence structures in top quark pairs.

Identified NAQC as a potential new quantum signature in high-energy physics.

Highlighted the importance of angular averaging effects.

Abstract

There is a growing interest in investigating top-quark systems using tools from quantum information theory. A key peculiarity of the top quark is that it decays before hadronization or spin decorrelation occurs, thereby preserving its spin information. This unique property enables direct access to spin correlations, making the top quark an ideal candidate for probing fundamental quantum correlations in high-energy physics processes. A wide range of concepts from quantum information theory, such as entanglement, Bell nonlocality, quantum steering, quantum discord, and fidelity, have been investigated in this context. Several of these measures have been employed as diagnostic tools to test the Standard Model and to search for possible signatures of physics beyond. However, the $\textit{nonlocal advantage of quantum coherence}$ (NAQC) has remained largely unexplored in this context. In this work, we present a detailed investigation of the NAQC in top quark pair production. We employ two complementary NAQC measures based on the $l_{1}$-norm and the relative entropy of coherence. We also study the effect of angular averaging on these measures. Our findings reveal rich coherence structures and highlight NAQC as potentially a novel and complementary quantum signature in high-energy physics systems.