Probing the Standard Model with Higgs signal rates from the Tevatron, the LHC and a future ILC

Abstract

We explore the room for possible deviations from the Standard Model (SM) Higgs boson coupling structure in a systematic study of Higgs coupling scale factor (κ) benchmark scenarios using the latest signal rate measurements from the Tevatron and LHC experiments. We employ χ 2 fits performed with HiggsSignals, which takes into account detailed information on signal efficiencies and major correlations of theoretical and experimental uncertainties. All considered scenarios allow for additional non-standard Higgs boson decay modes, and various assumptions for constraining the total decay width are discussed. No significant deviations from the SM Higgs boson coupling structure are found in any of the investigated benchmark scenarios. We derive upper limits on an additional (undetectable) Higgs decay mode under the assumption that the Higgs couplings to weak gauge bosons do not exceed the SM prediction. We furthermore discuss the capabilities of future facilities for probing deviations from the SM Higgs couplings, comparing the high luminosity upgrade of the LHC with a future International Linear Collider (ILC), where for the latter various energy and luminosity scenarios are considered. At the ILC modelindependent measurements of the coupling structure can be performed, and we provide estimates of the precision that can be achieved.

The Higgs legacy of the LHC Run I

“…In the past, SFitter has been one of the driving forces to answer the first [7][8][9][10][11][12][13][14][15][16][17] and third [18] questions. The second question has been tackled by Higgs specialized tools, for example presented in refs.…”

“…The current limit on invisible Higgs decays in the full Higgs couplings analysis is around 10%. Obviously, for a dedicated analysis with a more constraining model assumption the limits will be stronger [14][15][16][17].…”

Singlet-Doublet model: dark matter searches and LHC constraints

“…New invisible decay modes of the Higgs would reduce all visible branching fractions, hence the invisible branching ratio can be constrained by fits to the observed decay rates. In the following we employ the following limit: BR(h → invisible) < 26% (95% CL) [42].…”

The gauge-Higgs legacy of the LHC Run I

“…Already the LHC Run I allowed ATLAS and CMS to perform a large number of tests of the nature of the observed resonance, but no significant deviations from the Standard Model properties were observed for example in the Higgs production and decay rates [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. On the other hand, it is important to remind ourselves that the current constraints are still at a precision level for which no significant deviations would be expected in weakly interacting models of new physics [24].…”