VHH Production at the High-Luminosity LHC

We study the phenomenology of associated production of a vector boson with a pair of Higgs bosons (VHH at the High-Luminosity LHC (HL-LHC). Despite the low rate of this channel, the scaling of the cross section suggests a measurement could be a useful probe of modifications of the trilinear Higgs boson coupling and anomalous interactions in the gauge-Higgs sector. We focus on both WHH and ZHH production, using the leptonic ( $ W\rightarrow l \nu$ , $ Z \rightarrow ll$ , $ Z\rightarrow \nu \nu$ decay modes of the vector bosons and the $ HH \rightarrow 4b$ di-Higgs decay mode. We show that top pair backgrounds are problematic for the $ W\rightarrow l \nu$ and $ Z\rightarrow \nu \nu$ channels, leaving $ Z \rightarrow ll$ as the most promising decay mode. However, even for this channel, we find limited sensitivity due to a low signal rate. We discuss some potential avenues for improvement.