Search

Abstract The program N2HDECAY calculates the branching ratios and decay widths of the Higgs bosons of the Next-to-Two-Higgs-Doublet Model (N2HDM). The code incorporates the dominant higher-order effects by including QCD corrections and off-shell decay modes. The N2HDM is an extension of the Standard Model by a Higgs doublet and a real Higgs singlet. Its phenomenology can change dramatically depending on which global symmetries are broken by electroweak symmetry breaking. It can feature a large visible Higgs sector in the broken phase, behave like a 2HDM with scalar singlet dark matter in the dark singlet phase, or, in the inert doublet phase, extend an inert doublet model by mixing a singlet with the SM Higgs boson. N2HDECAY provides precise predictions for the decays of the Higgs bosons in all of these phases. Program summary Program Title: N2HDECAY Program Files doi: http://dx.doi.org/10.17632/n45d9zd5xz.1 Licensing provisions: GPLv2 Programming language: Fortran 77 Nature of problem: Calculation of branching ratios and total widths for the Higgs bosons and the top-quark in the N2HDM. To achieve a high precision, the decay widths are calculated including all available QCD and off-shell corrections. Solution method: The code calculates all required Higgs couplings from a standard set of N2HDM input parameters. The computations of the decay widths use analytic formulas for all two particle final states. Off-shell decays are integrated numerically and a linear interpolation over the resonance is performed. [ABSTRACT FROM AUTHOR]

The codes HiggsBounds and HiggsSignals compare model predictions of BSM models with extended scalar sectors to searches for additional scalars and to measurements of the detected Higgs boson at 125 GeV. We present a unification and extension of the functionalities provided by both codes into the new HiggsTools framework. The codes have been re-written in modern C++ with native Python and Mathematica interfaces for easy interactive use. We discuss the user interface for providing model predictions, now part of the new sub-library HiggsPredictions, which also provides access to many cross sections and branching ratios for reference models such as the SM. HiggsBounds now implements experimental limits purely through json data files, can better handle clusters of BSM particles of similar masses (even for complicated search topologies), and features an improved handling of mass uncertainties. Moreover, it now contains an extended list of Higgs-boson pair production searches and doubly-charged Higgs boson searches. In HiggsSignals, the treatment of different types of measurements has been unified, both in the χ 2 computation and in the data file format used to implement experimental results. Program title: HiggsTools CPC Library link to program files: https://doi.org/10.17632/b25smy28cj.1 Developer's repository link: https://gitlab.com/higgsbounds/higgstools Licensing provisions: GPLv3 Programming language: C++, Python, Mathematica Journal reference of previous version: P. Bechtle, O. Brein, S. Heinemeyer, G. Weiglein, K.E. Williams, Comput. Phys. Commun. 182 (2011), 2605-2631 Does the new version supersede the previous version?: Yes Reasons for the new version: This version extends the functionality of the previous versions and is re-written in modern C++. Summary of revisions: List of included Higgs-boson searches and Higgs-boson rate measurements has been expanded. Nature of problem: Determine whether a parameter point of a given model is excluded or allowed by LEP and LHC Higgs boson search results, and whether this model point is in agreement with the LHC Higgs-boson rate measurements. Solution method: Exclusion by Higgs boson searches: The most sensitive channel from LEP and LHC searches is determined and subsequently applied to test this parameter point for each Higgs boson of the model under consideration. The test requires as input, model predictions for the Higgs boson masses, branching ratios and ratios of production cross sections with respect to reference values. Agreement with LHC Higgs-boson rate measurements: A χ 2 value is calculated based on the available LHC rate measurements. This calculation requires as input model predictions for the Higgs boson(s) at ∼125 GeV. Additional comments including restrictions and unusual features: Assumes that the narrow width approximation is applicable in the model under consideration and that the model does not predict a significant change to the signature of the background processes or the kinematical distributions of the signal cross sections. [ABSTRACT FROM AUTHOR]

We point out the importance of the decay channels A→Zh and H→VV in the wrong-sign limit of the two-Higgs-doublet model (2HDM) of type II. They can be the dominant decay modes at moderate values of tanβ, even if the (pseudo)scalar mass is above the threshold where the decay into a pair of top quarks is kinematically open. Accordingly, large cross sections pp→A→Zh and pp→H→VV are obtained and currently probed by the LHC experiments, yielding conclusive statements about the remaining parameter space of the wrong-sign limit. In addition, mild excesses--as recently found in the ATLAS analysis bb→A→Zh--could be explained. The wrong-sign limit makes other important testable predictions for the light Higgs boson couplings. [ABSTRACT FROM AUTHOR]

We discuss the phenomenology of several beyond the Standard Model (SM) extensions that include extended Higgs sectors. The models discussed are the SM extended by a complex singlet field, the 2-Higgs-doublet model with a CP-conserving and a CP-violating scalar sector, the singlet extension of the 2-Higgs-doublet model, and the next-to-minimal supersymmetric SM extension. All the above models have at least three neutral scalars, with one being the 125 GeV Higgs boson. This common feature allows us to compare the production and decay rates of the other two scalars and therefore to compare their behavior at future electron-positron colliders. Using predictions on the expected precision of the 125 GeV Higgs boson couplings at these colliders we are able to obtain the allowed admixtures of either a singlet or a pseudoscalar to the observed 125 GeV scalar. Therefore, even if no new scalar is found, the expected precision at future electron-positron colliders, such as CLIC, will certainly contribute to a clearer picture of the nature of the discovered Higgs boson. [ABSTRACT FROM AUTHOR]