An effective gauge-Higgs operators analysis of new physics associated with the Higgs

TL;DR

The paper develops a model-independent EFT framework using gauge–invariant dimension-6 operators to parameterize new physics coupled to the Higgs. By computing modifications to Higgs production and decays, and linking them with EDM and g−2 constraints, it performs a global fit to current LHC data and low-energy observables. The analysis finds substantial room for NP within SM theoretical uncertainties, predicts robust relations such as μ_{ZZ} ≈ μ_{WW} with 0.6 ≤ μ_{WW,ZZ} ≤ 1.4 at 95% CL, and shows EDMs strongly constrain CP-odd components, with CP-odd effects potentially large in h→γγ and h→γZ channels. It also discusses possible UV completions and how upcoming Higgs pair measurements and spin-correlation studies could lift degeneracies and test CP-odd predictions.

Abstract

We study the new physics(NP) related to the recent discovered 125 GeV Higgs by employing an important subset of the standard model(SM) gauge invariant dimension-six operators constructed by the the SM Higgs and gauge fields. Explicitly, we perform a model-independent study on the production and decays of the Higgs, the electric dipole moments(EDM) of the neutron and the electron, and we take into account the anomalous magnetic dipole moments of muon and electron as well. We find that, even all Higgs decay channels agree with the SM predictions, the SM theoretical uncertainties provide a lot of room to host NP associated with the 125 GeV boson. A linear relation is revealed in our numerical study that $μ_{ZZ}\simeq μ_{WW}$ and $ 0.6 \lesssim μ_{ZZ,WW} \lesssim 1.4$ at 95% CL with or without the EDM's constraints. The neutron and electron EDM's severely constrain the relevant Wilson coefficients. Therefore the CP violating components in the $h\rightarrow WW, ZZ$ channels are too small, $\sim{\cal O}(10^{-5})$, to be detected at LHC. However, we point out that even the parity of the 125GeV boson has been largely determined to be even in the $h\to ZZ$ channel, one should pay special attention to the potentially large CP violation in the $h\to γγ$ and $h\to γZ$ channels. This should be seriously checked in the future spin correlation experiments.

Figures (11)

• Figure 1: The 1-loop contributions to electron and quark EDMs and charged lepton g-2. The gray bulbs represent the effective gauge-Higgs operators. Note that the mirror image diagrams are not displayed.
• Figure 2: The $1\sigma$ correlations between: (a) $\alpha_{\gamma\gamma}$ and $\gamma_{gg}$, (b) $\alpha_{WW}$ and $\gamma_{gg}$, (c)$\alpha_{ZZ}$ and $\gamma_{gg}$, (d)$\alpha_{\gamma Z}$ and $\gamma_{gg}$. The best fit locations are marked by dots.
• Figure 3: The $95\%$CL allowed region in (a-f) the Wilson coefficient space, and (g-i) the $hVV$ couplings, by using the LHC data (blue/darker) and the SM predictions(light brown/lighter). The best fit location is shown at the dot(cross) for LHC data (SM). The minimum $\chi^2 = 6.413 (0.0)$ for LHC data(SM). In subdiagram(b), we only display the SM like allowed region for $c_3$.
• Figure 4: The $95\%$CL correlations between the of $h\to W W^*$ and $h\to Z Z^*$ decay rate ratios, sub-diagram (a), and signal strength, sub-diagram (b). Where the best fit point is marked by the dot/cross, and the blue (darker)/ brown(lighter) region is for using the LHC/SM data.
• Figure 5: The $95\%$CL allowed region in (a-f) the Wilson coefficient space, and (g-i) in the Higgs-gauge couplings space, by using Higgs data, EDM, and AMDM. The blue(darker) and light brown(lighter) regions are for using the LHC data and the SM predictions respectively. The best fit location is shown at the dot(cross) for LHC data (SM). The corresponding minimum $\chi^2 = 15.89 (9.63)$ for LHC data(SM). In sub diagram (b), only the SM-like $c_3$ region is shown.