Jet angular correlation in vector-boson fusion processes at hadron colliders

TL;DR

This paper analyzes jet angular correlations in vector-boson fusion processes at hadron colliders, revealing how these correlations encode the spin and CP properties of Higgs bosons and gravitons, with explicit helicity amplitude calculations.

Contribution

It provides explicit helicity amplitudes for VBF subprocesses and demonstrates their dominance under certain selection cuts, elucidating jet angular correlations related to particle spin and CP nature.

Findings

VBF amplitudes dominate for relevant processes with proper cuts

Jet azimuthal correlations encode spin and CP information

Off-shell vector-boson currents reduce to splitting amplitudes in collinear limit

Abstract

Higgs boson and massive-graviton productions in association with two jets via vector-boson fusion (VBF) processes and their decays into a vector-boson pair at hadron colliders are studied. They include scalar and tensor boson production processes via weak-boson fusion in quark-quark collisions, gluon fusion in quark-quark, quark-gluon and gluon-gluon collisions, as well as their decays into a pair of weak bosons or virtual gluons which subsequently decay into $\ell\bar\ell$, $q\bar q$ or $gg$. We give the helicity amplitudes explicitly for all the VBF subprocesses, and show that the VBF amplitudes dominate the exact matrix elements not only for the weak-boson fusion processes but also for all the gluon fusion processes when appropriate selection cuts are applied, such as a large rapidity separation between two jets and a slicing cut for the transverse momenta of the jets. We also show that our off-shell vector-boson current amplitudes reduce to the standard quark and gluon splitting amplitudes with appropriate gluon-polarization phases in the collinear limit. Nontrivial azimuthal angle correlations of the jets in the production and in the decay of massive spin-0 and -2 bosons are manifestly expressed as the quantum interference among different helicity states of the intermediate vector-bosons. Those correlations reflect the spin and the CP nature of the Higgs bosons and the massive gravitons.