Higgs-boson visible and invisible constraints on hidden sectors
Thomas Biekötter, Mathias Pierre
Abstract
Abstract We investigate the impact of interactions between hidden sectors and the discovered Higgs boson $$h_{125}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>h</mml:mi> <mml:mn>125</mml:mn> </mml:msub> </mml:math> , allowing for additional invisible decay channels of $$h_{125}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>h</mml:mi> <mml:mn>125</mml:mn> </mml:msub> </mml:math> . We perform $$\chi ^2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>χ</mml:mi> <mml:mn>2</mml:mn> </mml:msup> </mml:math> -fits to the measurements of the Higgs-boson cross sections as a function of the invisible branching ratio and different combinations of coupling modifiers, where the latter quantify modifications of the couplings of $$h_{125}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>h</mml:mi> <mml:mn>125</mml:mn> </mml:msub> </mml:math> compared to the predictions of the Standard Model. We present generic results in terms of exclusion limits on the coupling modifiers and the invisible branching ratio of $$h_{125}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>h</mml:mi> <mml:mn>125</mml:mn> </mml:msub> </mml:math> . Additionally, we apply our results to a variety of concrete model realizations containing a hidden sector: dark matter within Higgs- and singlet-portal scenarios, models featuring (pseudo) Nambu–Goldstone bosons and two Higgs doublet extensions. One of the main conclusions of our work is that in a wide class of models the indirect constraints resulting from the measurements of the cross sections of $$h_{125}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>h</mml:mi> <mml:mn>125</mml:mn> </mml:msub> </mml:math> provide substantially stronger constraints on the invisible Higgs-boson branching ratio compared to the direct limits obtained from searches for the invisible decay of $$h_{125}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>h</mml:mi> <mml:mn>125</mml:mn> </mml:msub> </mml:math> . However, we demonstrate that the presence of an invisible decay mode of $$h_{125}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>h</mml:mi> <mml:mn>125</mml:mn> </mml:msub> </mml:math> can also open up parameter space regions which otherwise would be excluded as a result of the indirect constraints. As a byproduct of our analysis, we show that in light of the new results from the LZ collaboration a fermionic DM candidate within the simplest Higgs-portal scenario is ruled out under standard assumptions.