Probing light Yukawa couplings in Higgs pair production

TL;DR

This paper explores how modifications to light quark Yukawa couplings could be constrained by double-Higgs production at the LHC, using a model-independent approach and considering effective field theories.

Contribution

It provides a novel analysis of potential bounds on light quark Yukawa couplings through double-Higgs production, incorporating both linear and non-linear effective field theories.

Findings

Estimated exclusion bounds on light quark Yukawa coupling modifications.

Analyzed the $b\bar{b}\gamma\gamma$ final state for signal detection.

Compared linear and non-linear EFT frameworks for coupling modifications.

Abstract

One of the puzzles of the SM is the large hierarchy between the Yukawa couplings of different flavours. Yukawa couplings of the first and the second generation are constrained only very weakly so far. However, one can obtain large deviations in the Yukawa couplings in several New Physics (NP) models, such as e.g. models with new vector-like quarks, or new Higgs bosons that couple naturally to individual fermion families. In this work, we investigate the potential bounds on the NP Higgs Yukawa couplings modification $ \kappa_f$ for light quarks from double-Higgs at the LHC, starting from a model independent formalism. We have looked at the two Higgs boson final state $ b \bar b \gamma \gamma $, and the relevant experimental cuts to reduce backgrounds and estimated the potential exclusion bounds for $ \kappa_f$. We have considered both linear and non-linear effective field theory for the Higgs light quark coupling modifications.