New physics in resonant production of Higgs boson pairs

TL;DR

This paper proposes searching for an extended scalar sector at the LHC through resonant Higgs pair production, which could reveal new heavy Higgs particles and measure their couplings with high precision.

Contribution

It introduces a method to detect heavy Higgs resonances via $hh$ production and analyzes the potential to measure scalar and top Yukawa couplings accurately.

Findings

Resonant $hh$ production can be observed for $M_H<$ 1 TeV.

Scalar and top Yukawa couplings can be measured with 10-20% accuracy.

The sign of the couplings can be inferred from interference effects in the lineshape.

Abstract

We advocate a search for an extended scalar sector at the LHC via $hh$ production, where $h$ is the 125 GeV Higgs boson. A resonance feature in the $hh$ invariant mass is a smoking gun of an $s$-channel heavy Higgs resonance, $H$. With one $h$ decaying to two photons and the other decaying to $b$-quarks, the resonant signal may be discoverable above the $hh$ continuum background for $M_H<$ 1 TeV. The product of the scalar and top Yukawa couplings can be measured to better than $10-20\%$ accuracy, and its sign can be inferred from the $hh$ lineshape via interference effects.