Probing Extended Scalar Sectors with Precision $e^{+}{e}^{-}\to Zh$ and Higgs Diphoton Studies

Abstract

We compute the one-loop corrections to $\ddot{I}ƒ(e^{+}{e}^{-}\to Zh)$ arising from representative extended Standard Model scalar sector scenarios. According to the new scalar $\mathrm{SU}(2{)}_{\mathrm{L}}$ 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 $\ddot{I}ƒ(e^{+}{e}^{-}\to Zh)$, studies of the Higgsstrahlung process will probe extended scalar sector particle spectrum and interactions in a manner complementary to direct searches at the Large Hadron Collider and possible future $pp$ colliders. We also compare with the sensitivity of future Higgs diphoton decay rate measurements. We find that the $\ddot{I}ƒ(e^{+}{e}^{-}\to Zh)$ and $\hat{I}“(h\to {\hat{I}}^3{\hat{I}}^3)$ complementarity is particularly pronounced for the complex triplet model.

43 pages, 11 figures; v3: major revision requested by editor