The Community Planning Exercise (aka Snowmass), sponsored by the Division of Particles and Fields of the APS, brings together international partners to investigate the state of the field and promising new possibilities for future study. In this talk we will review the current state of the studies described in the Letters of Interest (LoI) submitted for study of the Higgs boson properties with...
Searches for extra Higgs bosons are quite important for a direct test of models with extended Higgs sectors. On the other hand, recent LHC data indicates that properties of the discovered Higgs boson are consistent with the SM Higgs boson within the error.
This favors a nearly alignment scenario in models with extended Higgs sectors, where the discovered Higgs boson couplings are almost the...
We compute the one-loop corrections to $\sigma(e^+e^-\to Zh)$ arising from representative extended Standard Model scalar sector scenarios. According to the new scalar SU(2)L representations, we consider the inert doublet, real and complex triplet, quintuplet, and septuplet models. With the sub-percent level precision expected for prospective future $e+e-$ collider measurements of...
We demonstrate how probes of CP-violating observables in Higgs di-tau decays at prospective future lepton colliders could provide a test of weak scale baryogenesis with significant discovery potential. Measurements at the Circular Electron Positron Collider, for example, could exclude a CP phase larger than $2.9^\circ$ ($5.6^\circ$) at 68\% (95\%) C.L. assuming the Standard Model value for the...
We obtain the upper bound on the new physics scale as a function
of the Higgs coupling deviation factor by considering the perturbative
unitarity of $2\to2$ scattering amplitudes among the longitudinally
polarized electroweak gauge bosons and the Higgs bosons.
We estimate the unitarity bound in a new effective field theory
which parameterizes the sizable non-decoupling effects from...
The HEFT is the most general effective field theory with non-linearly realized electroweak symmetry, but it cannot treat the production or decay processes of new particles. In the previous work, we extend the HEFT so that it includes the arbitrary number of neutral and charged scalar fields. In some of the BSM models such as composite Higgs models, however, the SM fermion partners are...
