Quantum Veto Parton Shower Algorithm in the Conformal Window

Abstract

We develop a quantum veto parton shower algorithm for a confining dark sector with gauge symmetry $\mathrm{SU}(3)_D \times \mathrm{U}(1)_D$ operating in the conformal window ($N_C = 3$, $N_F = 12$). The non-Abelian gauge coupling exhibits two-loop running toward an infrared fixed point before decoupling at a finite dark-quark mass threshold, while the dark quarks carry non-degenerate $\mathrm{U}(1)_D$ charges with unitary flavor mixing between the interaction and mass bases. Shower evolution proceeds coherently in the interaction basis, with states prepared and measured in the mass basis. Compared with the classical Markovian shower, the flavor-coherent quantum simulation produces a significantly enhanced zero-emission rate, and a characteristic U-shaped mass-eigenstate spectrum. Furthermore, energy-energy correlators exhibit approximate linearity in the double-logarithmic coordinates over an intermediate angular range, suggesting power-law scaling in that region. This framework demonstrates the capability of quantum algorithms to capture multi-flavor quantum interference in strongly interacting hidden sectors.