Diquark Higgs at LHC

TL;DR

The paper explores the theoretical existence and potential detection of color sextet diquark Higgs fields at the LHC, which could signal new physics beyond conventional grand unification, and discusses their phenomenological constraints.

Contribution

It introduces a class of models where light diquark Higgs fields naturally appear at TeV scale and analyzes their detectability at the LHC and bounds from Tevatron data.

Findings

Diquark Higgs fields could be detected via decay to top pairs or single top plus jet at LHC.

Existing Tevatron data constrains the diquark Higgs mass to be above 400-500 GeV.

These fields provide a new avenue for probing unification models with TeV-scale physics.

Abstract

Existence of color sextet diquark Higgs fields with TeV masses will indicate a fundamentally different direction for unification than conventional grand unified theories. There is a class of partial unification models based on the gauge group $SU(2)_L\times SU(2)_R\times SU(4)_c$ that implement the seesaw mechanism for neutrino mass with seesaw scale around $10^{11}$ GeV, where indeed such light fields appear naturally despite the high gauge symmetry breaking scale. They couple only to up-type quarks in this model. We discuss phenomenological constraints on these fields and show that they could be detected at LHC via their decay to either $tt$ or single top + jet. We also find that existing Tevatron data gives a lower bound on its mass somewhere in the 400-500 GeV, for reasonable values of its coupling.