Quantum Discord and Steering in Top Quarks at the LHC

Quantum detection of new physics in top-quark pair production at the LHC

“…The information on the quantum correlations of the t t spin state is fully contained in the matrix C, and possibly relevant quantum observables, including entanglement, discord, JHEP03(2024)099 steerability, concurrence, and Bell non-locality, can be computed from it [2,3,5,6,8,10,30]. Among all, entanglement is the most readily accessible, and it is the one we shall focus on in the rest of this work.…”

“…Numerous studies based on simulations [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] have elaborated further on these ideas, providing evidence that several more quantum effects may be visible in data collected (and to be collected) at the LHC, as well as at future colliders. Apart from establishing entanglement, these measurements could also potentially detect a violation of Bell inequalities.…”

Quantum advantage beyond entanglement in Bayesian game theory

“…However, the benefit of geometric discord is limited as it can increase under local reversible operations [13]. There has been an increased focus in recent years on designing methods for witnessing quantum discord both theoretically, [14] and even experimentally at the large Hadron collider, demonstrating the increasing understanding in quantum discord [15]. Therefore, it is of paramount importance that further techniques are explored in order to witness quantum correlations beyond entanglement, where there is particular focus on devising experimentally feasible protocols.…”

BRST invariant formulation of the Bell-CHSH inequality in gauge field theories

“…It is worth underlining that, besides the pure theoretical aspects, Bell-CHSH inequality violations are receiving a recent attention from both phenomenological and experimental sides. In fact, many experimental tests in the high-energy context were proposed recently, for instance, in systems with top-quarks [23][24][25][26][27], Λ baryons [28], τ leptons and photons [29]. There are also proposals for testing experimentally the Bell-CHSH inequality in e + e − collisions [30], neutral meson physics [31], neutrino oscillations [32], charmonium [33,34] and positronium [35] decays, and in the Higgs boson decay into W bosons [36][37][38], see also [39][40][41].…”