Cornering dimension-6 $HVV$ interactions at high luminosity LHC: the role of event ratios

TL;DR

This paper proposes using ratios of Higgs event rates in different channels at the high-luminosity LHC to improve constraints on dimension-6 $HVV$ interactions, reducing uncertainties and narrowing parameter ranges.

Contribution

It introduces a novel ratio-based method to enhance sensitivity to $HVV$ interactions, surpassing previous constraints from electroweak and Higgs data.

Findings

Projected limits surpass previous bounds.

Ratios effectively cancel theoretical uncertainties.

Parameter ranges are significantly narrowed.

Abstract

We suggest a way of improving the probes on dimension-6 CP-conserving $HVV$ interactions ($V$ = $W$, $Z$, $\gamma$), from the LHC data on the Higgs boson to be available in the 14 TeV run with an integrated luminosity of $3000$ fb$^{-1}$. We find that the ratios of total rates in different channels can be quite useful in this respect. This includes ratios of event rates in (a) different final states for the Higgs produced by the same production mechanism, and (b) the same final state from two different production modes. While most theoretical uncertainties cancel in the former, the latter helps in the case of those operators which shift the numerator and denominator in opposite directions. Our analysis, incorporating theoretical, systematic and statistical uncertain, leads to projected limits that are better than the strongest ones obtained so far from precision electroweak as well as LHC Higgs data. Moreover, values of the coefficients of the dimension-6 operators, which are allowed in disjoint intervals, can have their ranges narrowed down substantially in our approach.