Resolving the degeneracy in top quark Yukawa coupling with Higgs pair production

Abstract

The top quark Yukawa coupling (yt) can be modified by two dimension-six operators OH and Oy with the corresponding Wilson coefficients cH and cy, whose individual contribution cannot be distinguished by measuring yt alone. However, such a degeneracy can be resolved with Higgs boson pair production. In this work we explore the potential of resolving the degeneracy of the unknown Wilson coefficients cH and cy at the 14 TeV LHC and the 100 TeV hadron colliders. Combining the information of the single Higgs production, tt¯h associated production and Higgs pair production, the individual contribution of cH and cy to yt can be separated. Regardless of the value of cH, the Higgs pair production can give a strong constraint on cy at the 100 TeV hadron collider. We further show that it is possible to differentiate various cy and ct values predicted in several benchmark models.