Two-loop QCD corrections to e + e − → Z * → J / ψ + J / ψ
Abstract
We present a next-to-next-to-leading-order (NNLO) calculation within the nonrelativistic QCD framework for the process e + e − → Z * → J / ψ + J / ψ . We find that the NNLO contribution is two to three times larger than the next-to-leading-order contribution, which itself is already three to five times larger than the leading-order result. In the high-energy limit, we provide analytic expressions for the leading-power coefficients in the asymptotic expansion of the two-loop amplitudes. Our results are directly applicable to the bottomonium process Z → ϒ + ϒ . Using the obtained hadronic amplitudes, we predict the decay width of the Z boson into these rare dicharmonium and dibottomonium final states.
Fields of Study & Subjects
Particle physics theoretical and experimental studies
Quantum Chromodynamics and Particle Interactions
High-Energy Particle Collisions Research
Publication details
- Journal / source
- Physical review. D/Physical review. D.
- Publisher
- American Physical Society (APS)
- Volume
- 113
- Issue
- 9
- Publication date
- 22 April 2026
- Language
- EN