Speaker
Description
The absence of conclusive evidence for beyond the Standard Model (BSM) physics at the Large Hadron Collider (LHC) motivates the exploration of unconventional signatures alongside precision measurements. In this work, we investigate the Georgi-Machacek model, an extension of the Standard Model scalar sector with one complex and one real $SU(2)$ triplet, which allows sizable triplet vacuum expectation values (VEVs) consistent with electroweak precision constraints. While existing searches for triplet scalars primarily target extreme VEV regimes through the decay of the doubly charged scalars into same-sign dileptons or same-sign $W$ boson pairs, we focus on the intermediate VEV region. In this regime, triplet-dominated scalars exhibit delayed decays into diboson alone or both the diboson and dilepton final states, leading to distinctive collider signatures. Since these signatures are highly sensitively to the presence of Yukawa interactions, we analyze scenarios both with and without lepton-number-violating triplet Yukawa coupling. Including relevant Standard Model backgrounds, we assess the discovery prospects at the High-Luminosity LHC (HL-LHC) and the Future Circular Collider in hadron--hadron mode (FCC-hh). Our results highlight the importance of intermediate VEV regimes and demonstrate that they provide complementary avenues to probe triplet scalar extensions of the Standard Model.