The leptonic future of the Higgs

Abstract

Abstract Precision study of electroweak symmetry breaking strongly motivates the construction of a lepton collider with center-of-mass energy of at least 240 GeV. Besides Higgsstrahlung (e + e − → hZ), such a collider would measure weak boson pair production (e + e − → WW) with an astonishing precision. The weak-boson-fusion production process ( e + e − → ν ν ¯ h $$ {e}^{+}{e}^{-}\to \nu \overline{\nu}h $$ ) provides an increasingly powerful handle at higher center-of-mass energies. High energies also benefit the associated top-Higgs production ( e + e − → t t ¯ h $$ {e}^{+}{e}^{-}\to t\overline{t}h $$ ) that is crucial to constrain directly the top Yukawa coupling. The impact and complementarity of differential measurements, at different center-of-mass energies and for several beam polarization configurations, are studied in a global effective-field-theory framework. We define a global determinant parameter (GDP) which characterizes the overall strengthening of constraints independently of the choice of operator basis. The reach of the CEPC, CLIC, FCC-ee, and ILC designs is assessed.

Keywords

• Beyond Standard Model
• Effective Field Theories
• Higgs Physics