Optimizing Entanglement and Bell Inequality Violation in Top Anti-Top Events

• URL: http://arxiv.org/abs/2407.01672v1
• Date: Mon, 1 Jul 2024 18:00:01 GMT
• Title: Optimizing Entanglement and Bell Inequality Violation in Top Anti-Top Events
• Authors: Kun Cheng, Tao Han, Matthew Low,
• Abstract summary: We show that the basis which diagonalizes the spin-spin correlations is optimal for maximizing spin correlations, entanglement, and Bell inequality violation. We present the sensitivity for entanglement and Bell inequality violation in $tbar t$ events at the LHC and a future $e+e-$ collider.
• Score: 5.151248813215795
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: A top quark and an anti-top quark produced together at colliders have correlated spins. These spins constitute a quantum state that can exhibit entanglement and violate Bell's inequality. In realistic collider experiments, most analyses allow the axes, as well the Lorentz frame to vary event-by-event, thus introducing a dependence on the choice of event-dependent basis leading us to adopt "fictitious states," rather than genuine quantum states. The basis dependence of fictitious states allows for an optimization procedure, which makes the usage of fictitious states advantageous in measuring entanglement and Bell inequality violation. In this work, we show analytically that the basis which diagonalizes the spin-spin correlations is optimal for maximizing spin correlations, entanglement, and Bell inequality violation. We show that the optimal basis is approximately the same as the fixed beam basis (or the rotated beam basis) near the $t\bar t$ production threshold, while it approaches the helicity basis far above threshold. Using this basis, we present the sensitivity for entanglement and Bell inequality violation in $t\bar t$ events at the LHC and a future $e^+e^-$ collider. Since observing Bell inequality violation appears to be quite challenging experimentally, and requires a large dataset in collider experiments, choosing the optimal basis is crucially important to observe Bell inequality violation. Our method and general approach are equally applicable to other systems beyond $t \bar t$, including interactions beyond the Standard Model.

Related papers

• Optimizing random local Hamiltonians by dissipation [44.99833362998488]
  We prove that a simplified quantum Gibbs sampling algorithm achieves a $Omega(frac1k)$-fraction approximation of the optimum. Our results suggest that finding low-energy states for sparsified (quasi)local spin and fermionic models is quantumly easy but classically nontrivial.
  arXiv  Detail & Related papers  (2024-11-04T20:21:16Z)
• An improved Bell-CHSH observable for gauge boson pairs [0.0]
  In this work, we consider Bell inequalities based on squares of spin operators. We find that our new choice of Bell operator has promising properties regarding states seen at colliders. We also conduct the first investigation of Bell violation in a system involving gauge bosons mediating different interactions.
  arXiv  Detail & Related papers  (2024-10-23T16:54:15Z)
• Nonlocality under Jaynes-Cummings evolution: beyond pseudospin operators [44.99833362998488]
  We re-visit the generation and evolution of (Bell) nonlocality in hybrid scenarios whose dynamics is determined by the Jaynes-Cummings Hamiltonian. Recent results on the optimal Bell violation in qubit-qudit systems show that the nonlocality is much greater than previously estimated.
  arXiv  Detail & Related papers  (2024-10-14T16:01:23Z)
• Entanglement and Bell inequality violation in $B\to \it{ΦΦ}$ decays [0.0]
  We show that the present LHCb data allows access to entanglement and to the Bell inequality violation with a significance exceeding the 5$sigma$ threshold. This demonstrates that the strong and electroweak interactions responsible for the $B$ meson decay act as a source of entanglement and the quantum mechanics nature of high-energy phenomena.
  arXiv  Detail & Related papers  (2024-08-09T11:46:06Z)
• Some consequences of Sica's approach to Bell's inequalities [55.2480439325792]
  Louis Sica derived Bell's inequalities from the hypothesis that the time series of outcomes observed in one station does not change if the setting in the other station is changed. In this paper, Sica's approach is extended to series with non ideal efficiency and to the actual time structure of experimental data.
  arXiv  Detail & Related papers  (2024-03-05T13:59:52Z)
• Optimizing Fictitious States for Bell Inequality Violation in Bipartite Qubit Systems [5.151248813215795]
  We show that if Bell inequality violation is observed with a fictitious state, then it implies the same for a quantum sub-state. We further show analytically that the basis which diagonalizes the spin-spin correlations is optimal for constructing fictitious states.
  arXiv  Detail & Related papers  (2023-11-15T18:05:44Z)
• Bell inequality is violated in $B^0\to J/\psi \, K^{\star}(892)^0$ decays [0.0]
  Entanglement is also present and the Bell inequality is violated in other decays of the $B$ mesons into vector mesons. We establish these distinguishing features of quantum mechanics at high energies in a collider setting.
  arXiv  Detail & Related papers  (2023-05-08T18:25:25Z)
• Observing super-quantum correlations across the exceptional point in a single, two-level trapped ion [48.7576911714538]
  In two-level quantum systems - qubits - unitary dynamics theoretically limit these quantum correlations to $2qrt2$ or 1.5 respectively. Here, using a dissipative, trapped $40$Ca$+$ ion governed by a two-level, non-Hermitian Hamiltonian, we observe correlation values up to 1.703(4) for the Leggett-Garg parameter $K_3$. These excesses occur across the exceptional point of the parity-time symmetric Hamiltonian responsible for the qubit's non-unitary, coherent dynamics.
  arXiv  Detail & Related papers  (2023-04-24T19:44:41Z)
• Quantum tops at the LHC: from entanglement to Bell inequalities [0.0]
  We introduce a unique set of observables suitable for both measurements, and then perform the corresponding analyses. We find that entanglement can be established at better than 5$sigma$ both at threshold as well as at high $p_T$ already in the LHC Run 2 dataset.
  arXiv  Detail & Related papers  (2021-10-19T17:07:28Z)
• Using Randomness to decide among Locality, Realism and Ergodicity [91.3755431537592]
  An experiment is proposed to find out, or at least to get an indication about, which one is false. The results of such experiment would be important not only to the foundations of Quantum Mechanics.
  arXiv  Detail & Related papers  (2020-01-06T19:26:32Z)
• Bell's theorem for trajectories [62.997667081978825]
  A trajectory is not an outcome of a quantum measurement, in the sense that there is no observable associated with it. We show how to overcome this problem by considering a special case of our generic inequality that can be experimentally tested point-by-point in time.
  arXiv  Detail & Related papers  (2020-01-03T01:40:44Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.