El entrelazamiento máximo en la dispersión de bosones de Higgs conduce a la duplicación de la simetría ✛ ✦

Resumen original

tal como lo escribieron los autores, en inglés arXiv:2505.00873v1

We consider 2-to-2 scatterings of Higgs bosons in a CP-conserving two-Higgs-doublet model (2HDM) and study the implication of maximizing the entanglement in the flavor space, where the two doublets $$\Phi_a$$, $$a=1,2$$, can be viewed as a qubit: $$\Phi_1=|0\rangle$$ and $$\Phi_2=|1\rangle$$. More specifically, we compute the scattering amplitudes for $$\Phi_a \Phi_b \to \Phi_c \Phi_d$$ and require the outgoing flavor entanglement to be maximal for a full product basis such as the computational basis, which consists of $$\{|00\rangle,|01\rangle,|10\rangle,|11\rangle\}$$. In the unbroken phase and turning off the gauge interactions, entanglement maximization results in the appearance of an $$U(2)\times U(2)$$ global symmetry among the quartic couplings, which in general is broken softly by the mass terms. Interestingly, once the Higgs bosons acquire vacuum expectation values, maximal entanglement enforces an exact $$U(2) \times U(2)$$ symmetry, which is spontaneously broken to $$U(1)\times U(1)$$. As a byproduct, this gives rise to Higgs alignment as well as to the existence of 6 massless Nambu-Goldstone bosons. The $$U(2)\times U(2)$$ symmetry can be gauged to lift the massless Goldstones, while maintaining maximal entanglement demands the presence of a discrete $$\mathrm{Z}_2$$ symmetry interchanging the two gauge sectors. The model is custodially invariant in the scalar sector, and the inclusion of fermions requires a mirror dark sector, related to the standard one by the $$\mathrm{Z}_2$$ symmetry.