Entanglement and Bell inequalities violation in $H\to ZZ$ with anomalous coupling

TL;DR

This paper investigates quantum entanglement and Bell inequality violations in Higgs decay to Z bosons, showing that entanglement persists even with anomalous couplings, which could have implications for beyond Standard Model physics.

Contribution

It demonstrates that the $ZZ$ state from Higgs decay remains entangled and violates Bell inequalities despite the presence of anomalous couplings, extending understanding of quantum correlations in particle physics.

Findings

$ZZ$ state is entangled for all anomalous couplings

Violates CGLMP inequality across coupling range

Supports quantum correlations in Higgs decay processes

Abstract

We discuss entanglement and violation of Bell-type inequalities for a system of two $Z$ bosons produced in Higgs decays. We take into account beyond the Standard Model (anomalous) coupling between $H$ and daughter bosons but we limit ourselves to an overall scalar $ZZ$ state (we exclude the possibility that $H$ contains a pseudo-scalar component). In particular we consider the case when each $Z$ decays further into fermion-antifermion pair. We find that a $ZZ$ state is entangled and violates the CGLMP inequality for all values of the (anomalous) coupling constant.