NLO QCD corrections to tri-boson production

TL;DR

The paper develops NLO QCD predictions for tri-boson production at the LHC (ZZZ, WWZ, WZZ, WWW) using the OPP integrand-level reduction for virtual amplitudes and dipole subtraction plus phase-space slicing for real emissions. It demonstrates large QCD corrections (K-factors around 2) and provides detailed transverse-momentum and rapidity distributions, validating the approach with cross-checks between independent methods. The work confirms the feasibility of the OPP method for complex multi-boson processes and delivers results useful for experimental analyses and the development of universal NLO tools. Overall, it establishes a robust framework for precise predictions of rare electroweak final states at high-energy colliders.

Abstract

We present a calculation of the NLO QCD corrections for the production of three vector bosons at the LHC, namely Z Z Z, W+ W- Z, W+ Z Z, and W+ W- W+ production. The virtual corrections are computed using the recently proposed method of reduction at the integrand level (OPP reduction). Concerning the contributions coming from real emission we used the dipole subtraction to treat the soft and collinear divergences. We find that the QCD corrections for these electroweak processes are in the range between 70 and 100 percent. As such they have to be considered in experimental studies of triple vector boson production at the LHC.

Figures (6)

• Figure 1: Tree-level structures of Feynman diagrams contributing to $q {\bar{q}} \to V V V$, where $V={Z,W}$. Dashed internal lines can represent W, Z, Goldstone bosons or photons.
• Figure 2:
• Figure 3: Additional NLO structures contributing in the production of $W^{+}W^{-}Z$, $W^{+} Z Z$, and $W^{+}W^{-}W^{+}$, that do not appear in the $Z Z Z$ case. Dashed internal lines can represent W, Z, Goldstone bosons or photons.
• Figure 4: Transverse momentum distribution, as defined in the text, for the four processes $pp \to VVV$: NLO (solid line) compared with the LO contribution (dashed line).
• Figure 5: $K-$factors, corresponding to the plots in Fig. \ref{['ptfig']}