Neutral Pseudoscalar Higgs Bosons Research Articles

Search for Higgs bosons decaying toaain theμμττfinal state inppcollisions ats=8 TeVwith the ATLAS experiment

A search for the decay to a pair of new particles of either the 125 GeV Higgs boson (h) or a second charge parity (CP)-even Higgs boson (H) is presented. The data set corresponds to an integrated luminosity of 20.3 fb−1 of pp collisions at s=8 TeV recorded by the ATLAS experiment at the LHC in 2012. The search was done in the context of the next-to-minimal supersymmetric standard model, in which the new particles are the lightest neutral pseudoscalar Higgs bosons (a). One of the two a bosons is required to decay to two muons while the other is required to decay to two τ leptons. No significant excess is observed above the expected backgrounds in the dimuon invariant mass range from 3.7 to 50 GeV. Upper limits are placed on the production of h→aa relative to the standard model gg→h production, assuming no coupling of the a boson to quarks. The most stringent limit is placed at 3.5% for ma=3.75 GeV. Upper limits are also placed on the production cross section of H→aa from 2.33 to 0.72 pb, for fixed ma=5 GeV with mH ranging from 100 to 500 GeV.Received 8 May 2015DOI:https://doi.org/10.1103/PhysRevD.92.052002This article is available under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.© 2015 CERN, for the ATLAS Collaboration

Search for Next-to-Minimal Supersymmetric Higgs Bosons in theh→aa→μμμμ,μμττChannels Usingpp¯Collisions ats=1.96 TeV

We report on a first search for production of the lightest neutral CP-even Higgs boson (h) in the next-to-minimal supersymmetric standard model, where h decays to a pair of neutral pseudoscalar Higgs bosons (a), using 4.2/fb of data recorded with the D0 detector at Fermilab. The a bosons are required to either both decay to mu^+mu^- or one to mu^+mu^- and the other to tau^+tau^-. No significant signal is observed, and we set limits on its production as functions of M_a and M_h.

Searches for MSSM Higgs Bosons with the DELPHI Detector up to $\sqrt{s} = 209~{\rm GeV}$

Searches for hA pair production and hZ production have been performed. Special emphasis has been put on searches, in which the Higgs can decay invisibly into neutralinos. The data collected by the DELPHI experiment at centre-of-mass energies between 191.6 and 201.7 Gev for the year 1999 and between 201.7 and 209.0 Gev for the ongoing data taking in 2000 has been used. These analyses are used, in combination with our results at lower energies, to set 95% confidence levels on the existence of a light neutral Higgs Boson h and a neutral pseudoscalar Higgs Boson A in a mass range of 85-115 GeV/c 2. Combining the searches for visible and invisible Higgs decays allows to obtain 95% confidence levels on the existance of h independent of the branching ratio into invisible decays, if the visible decays are taken to be the SM ones. The MSSM parameter space excluded by these searches has been determined.

Search for neutral Higgs bosons of the Minimal Supersymmetric Standard Model in e +e −interactions at [formula omitted]= 189 [formula omitted

A search for the lightest neutral scalar and neutral pseudoscalar Higgs bosons in the Minimal Supersymmetric Standard Model is performed using 176.4 pb −1 of integrated luminosity collected by L3 at a center-of-mass energy of 189 GeV . No signal is observed, and the data are consistent with the expected Standard Model background. Lower limits on the masses of the lightest neutral scalar and pseudoscalar Higgs bosons are given as a function of tan β. Lower mass limits for tan β>1 are set at the 95% confidence level to be m h >77.1 GeV and m A >77.1 GeV .

Search for neutral Higgs bosons in e $^+$ e $^-$ collisions at $\sqrt{s}=183$ GeV

Neutral Higgs bosons were searched for in the data collected by DELPHI at a centre-of-mass energy of 183 GeV, corresponding to an integrated luminosity of 54 pb\(^{-1}\). The production of the lightest neutral Higgs boson with either an on-shell Z boson or a neutral pseudo-scalar Higgs boson was analysed. Lower limits at the 95% confidence level were obtained on the Higgs boson masses. The limits are 85.7 GeV/\(c^2\) for the Standard Model Higgs boson and 74.4 GeV/\(c^2\) for the scalar and 75.3 GeV/\(c^2\) for the pseudo-scalar Higgs bosons as predicted by the minimal super-symmetric extension of the Standard Model with commonly used assumptions on the model parameters, plus the assumption that the mass of the pseudo-scalar boson is greater than 20 GeV/\(c^2\). These results significantly improve the limits reached with previous data.

Search for neutral Higgs bosons in e + e - collisions at √ {s}=183 GeV

Neutral Higgs bosons were searched for in the data collected by DELPHI at a centre-of-mass energy of 183 GeV, corresponding to an integrated luminosity of 54 pb-1. The production of the lightest neutral Higgs boson with either an on-shell Z boson or a neutral pseudo-scalar Higgs boson was analysed. Lower limits at the 95% confidence level were obtained on the Higgs boson masses. The limits are 85.7 GeV/c2 for the Standard Model Higgs boson and 74.4 GeV/c2 for the scalar and 75.3 GeV/c2 for the pseudo-scalar Higgs bosons as predicted by the minimal super-symmetric extension of the Standard Model with commonly used assumptions on the model parameters, plus the assumption that the mass of the pseudo-scalar boson is greater than 20 GeV/c2. These results significantly improve the limits reached with previous data.

Search for neutral Higgs bosons in e

Neutral Higgs bosons were searched for in the data collected by DELPHI at a centre-of-mass energy of 183 GeV, corresponding to an integrated luminosity of 54 pb −1 . The production of the lightest neutral Higgs boson with either an on-shell Z boson or a neutral pseudo-scalar Higgs boson was analysed. Lower limits at the 95% confidence level were obtained on the Higgs boson masses. The limits are 85.7 GeV/ c2 for the Standard Model Higgs boson and 74.4 GeV/ c2 for the scalar and 75.3 GeV/ c2 for the pseudo-scalar Higgs bosons as predicted by the minimal super-symmetric extension of the Standard Model with commonly used assumptions on the model parameters, plus the assumption that the mass of the pseudo-scalar boson is greater than 20 GeV/ c2 . These results significantly improve the limits reached with previous data.

Search for neutral Higgs bosons of the minimal supersymmetric standard model in e +e −interactions at [formula omitted] = 130 - 183 GeV

A search for the lightest neutral scalar and neutral pseudoscalar Higgs bosons in the Minimal Supersymmetric Standard Model is performed on data collected at LEP by the L3 detector at center-of-mass energies 130 GeV ≤ s ≤183 GeV . No significant excess of events is observed. Limits on the masses of the lightest neutral and pseudoscalar Higgs bosons are given as a function of tan β. Lower mass limits at the 95% confidence level are set at m h >70.7 GeV and m A >71.0 GeV .

Search for neutral and charged Higgs bosons in ${\rm e^+e^- \;}$ collisions at $\sqrt{s}$ = 161 GeV and 172 GeV

A search for neutral and charged Higgs bosons has been performed in the data collected by the {\sc DELPHI} detector at centre-of-mass energies of 161~GeV and 172~GeV. The analysis assumes either the pair-production of charged Higgs bosons, ${\mathrm H}^{\pm}$, or the production of the lightest neutral Higgs boson, h, with either a Z or a neutral pseudoscalar Higgs boson, A. All final state topologies expected from the decay of h and A %neutral Higgs particles into hadrons or a pair of $\tau$ leptons, and from the decay of ${\mathrm H}^{\pm}$ %charged Higgs bosons into a pair of quarks or a $\tau \nu_{\tau}$ pair have been considered. %In the case of the associated production with a Z boson, all decay %channels of the Z have been considered. %The case of a %Higgs boson decaying into invisible products has also been studied. %The results are interpreted %in the framework of the Standard Model and of its minimal supersymmetric %extension for the neutral Higgs bosons. %Results for the charged Higgs particles are deduced in the more %general two-doublet scheme. Lower limits at the 95\% confidence level have been obtained on the Higgs boson masses. The limits are 66.2~GeV/$c^2$ for h in the Standard Model, 59.5~GeV/$c^2$ for h and 51.0~GeV/$c^2$ for A in the minimal supersymmetric extension of the Standard Model and 51.5~GeV/$c^2$ for ${\mathrm H}^{\pm}$ in the general two-doublet scheme for ${\mathrm H}^{\pm}$ branching fractions into hadrons below 0.8.