Status of Higgs couplings after run 1 of the LHC

We provide an update of the global fits of the couplings of the 125.5 GeV Higgs boson using all publicly available experimental results from run 1 of the LHC as per summer 2014. The fits are done by means of the new public code Lilith 1.0. We present a selection of results given in terms of signal strengths, reduced couplings, and for the two-Higgs-doublet models of type I and II.

Figure 1

Combined signal strengths in the plane of $(\mathrm{ggF}+\mathrm{ttH})$ versus $(\mathrm{VBF}+\mathrm{VH})$ production, on the left for the $\gamma \gamma$, $Z{Z}^{*}$, $W{W}^{*}$ and $V{V}^{*}$ decay modes (the latter assuming $Z{Z}^{*}=W{W}^{*}$), on the right for the $b\overline{b}$ and $\tau \tau$ decay modes and their combination $b\overline{b}=\tau \tau$. The full (dashed) contours denote the 68.3% (95.4%) C.L. regions, derived by combining the ATLAS, CMS, and Tevatron results. The best-fit points are marked as stars, and the SM case by a black diamond.

Figure 2

Fits of $C_U$, $C_D$, and $C_V$ (left and middle panels) and resulting $C_g$ versus $C_{\gamma }$ (right panel). The central (red), intermediate (orange) and outer (yellow) areas are the 68.3%, 95.4%, and 99.7% C.L. regions, respectively. The best-fit points are marked as white stars. Invisible or undetected decays are assumed to be absent.

Figure 3

As Fig. 2 but for a two-parameter fit of $C_g$ and $C_{\gamma }$; in the left panel $\mathrm{\Delta }{C}_g=C_g-1$, $\mathrm{\Delta }{C}_{\gamma }=C_{\gamma }-1$ (SM values of $C_U$, $C_D$, $C_V$), while in the right panel $C_U$, $C_D$, $C_V$ are fixed to their best-fit values and hence $\mathrm{\Delta }{C}_g=C_g-1.01$, $\mathrm{\Delta }{C}_{\gamma }=C_{\gamma }-1.06$.

Figure 4

Fits of $\cos (\beta -\alpha )$ versus $\tan \beta$ for the 2HDM of type I (left) and of type II (right) for $m_h=125.5\mathrm{GeV}$. The central (red), intermediate (orange) and outer (yellow) areas are the 68.3%, 95.4%, and 99.7% C.L. regions, respectively. The best-fit points are marked as white stars. Decays into non-SM particles (such as $h\to AA$) are assumed to be absent.