Parameter Inference from Final-State Entanglement in Higgs Decays

Abstract:The decay out-states of unstable Standard Model (SM) particles provide a unique, well-defined intrinsic quantum-information probe of the SM parameter space. We use Higgs decays as a test case: after tracing out kinematics, we compute entanglement among final-state spins and colors across all decay channels and impose a near-maximal entanglement-entropy criterion. This criterion yields quantitative indications for fundamental parameters. Within the SM, the entanglement entropy exhibits a global maximum close to the observed Higgs mass and the measured $W$ mass, the latter being equivalent to the $SU(2)_L$ gauge coupling. In a two-parameter kappa framework, applying the same criterion points to an SM-like balance between vector and fermion couplings, constraining the ratio of the sector-wide rescalings. These results suggest that entanglement extremality can serve as a complementary handle on fundamental parameters.

arXiv:2511.17321 [hep-ph]

(or arXiv:2511.17321v2 [hep-ph] for this version)

https://doi.org/10.48550/arXiv.2511.17321 Focus to learn more arXiv-issued DOI via DataCite

Phys. Rev. D 114, 015036 (2026)

https://doi.org/10.1103/jynb-w9kq Focus to learn more DOI(s) linking to related resources

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