Azimuthal Angle Probe of Anomalous $HWW$ Couplings at a High Energy $ep$ Collider

A high energy $ep$ collider, such as the proposed LHeC, possesses the unique facility of permitting direct measurement of the $HWW$ coupling without contamination from the $HZZ$ coupling. At such a machine, the fusion of two $W$ bosons through the $HWW$ vertex would give rise to typical charged current events accompanied by a Higgs boson. We demonstrate that azimuthal angle correlations between the observable charged current final states could then be a sensitive probe of the nature of the $HWW$ vertex and hence of the $CP$ properties of the Higgs boson.

Figure 1

Higgs boson production at an $ep$ collider through $WW$ fusion and the $HWW$ vertex.

Figure 2

Azimuthal angle distributions in the SM and with anomalous $HWW$ couplings.

Figure 3

Exclusion plots obtainable by a study of the azimuthal angle distributions at the LHeC for the $CP$-even coupling $\lambda$ and the $CP$-odd coupling ${\lambda }^{\prime }$.