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arXiv:2403.18023

Tripartite entanglement and Bell non-locality in loop-induced Higgs boson decays

Roberto A. Morales

Published Mar 26, 2024• 2 citations
arXivHTMLPDF

Abstract

In this article, we study quantum entanglement properties of the three-body $H\toγl\bar{l}$ decays (for $l=e,μ,τ$) within the context of the Standard Model augmented with CP-violating interactions in the lepton Yukawa sector. Our aim is to elucidate the distribution of entanglement between the final photon, lepton and antilepton across the phase-space. These rare Higgs boson decays occur at 1-loop level, presenting a unique opportunity to scrutinize quantum correlations of fundamental interactions in tripartite systems by computing concurrence measures and investigating Bell non-locality. Moreover, we explore post-decay and autodistillation phenomena. Multipartite entanglement measures have much richer structure than those in the bipartite case, thus deserve more attention in collider phenomenology. In this line, we analyze here novel observables for these three-body Higgs boson decays, which can be extended to other multiparticle systems within the high-energy regime. We found that entanglement manifests among final particles, occasionally achieving a maximally entangled state in specific kinematical configurations. Also, these decay channels are promising for Bell non-locality tests but CP-effects are suppressed by lepton masses in this kind of observables.

DOI
10.48550/arxiv.2403.18023

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Abstract In this article, we study quantum entanglement properties of the three-body H→γllˉH\rightarrow \gamma l{\bar{l}}H→γllˉ H → γ l l ¯ decays (for l=e,μ,τl=e,\mu ,\tau l=e,μ,τ l = e , μ , τ ) within the context of the Standard Model augmented with CP-violating interactions in the lepton Yukawa sector. Our aim is to elucidate the distribution of entanglement between the final photon, lepton and antilepton across the phase-space. These rare Higgs boson decays occur at 1-loop level, presenting a unique opportunity to scrutinize quantum correlations of fundamental interactions in tripartite systems by computing concurrence measures and investigating Bell non-locality. Moreover, we explore post-decay and autodistillation phenomena. Multipartite entanglement measures have much richer structure than those in the bipartite case, thus deserve more attention in collider phenomenology. In this line, we analyze here novel observables for these three-body Higgs boson decays, which can be extended to other multiparticle systems within the high-energy regime. We found that entanglement manifests among final particles, occasionally achieving a maximally entangled state in specific kinematical configurations. Also, these decay channels are promising for Bell non-locality tests but CP-effects are suppressed by lepton masses in this kind of observables.
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Tripartite Entanglement in e+e−→ttˉZe^+ e^- \to t \bar{t} Ze+e−→ttˉZ
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The decays of the Higgs boson produce a state in which the spins of the decay products and the orbital angular momentum ( L ) are highly entangled. We obtain the tripartite density operator, as well as reduced operators, for the decay into two weak bosons. For H → Z Z in the four-lepton final state we also estimate the statistical sensitivity at the Large Hadron Collider and future upgrades, using a binned method to reconstruct the density operators from distributions. With the expected Run 3 data, establishing genuine tripartite entanglement would be possible beyond the 5 σ level. The violation of Bell inequalities involving the spins of the two weak bosons could also be established beyond the 5 σ level. Published by the American Physical Society 2024
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