Search for a fermiophobic Higgs at LEP 2

Bergische Universität Wuppertal, Wuppertal, North Rhine-Westphalia, Germany
Physics Letters B (Impact Factor: 6.13). 05/2001; 507(1-4):89-103. DOI: 10.1016/S0370-2693(01)00449-X


Higgs bosons predicted by the fermiophobic scenario within Two Higgs Doublets Models were searched for in the data collected by the DELPHI detector at centre-of-mass energies between 189 GeV and 202 GeV, corresponding to a total integrated luminosity of 380 pb−1. No signal was found and confidence limits were derived in the framework of possible extensions of the Standard Model Higgs sector.

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Available from: Martyn Davenport, Apr 22, 2014
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    ABSTRACT: We show that a general two-Higgs-doublet model with a very light CP-odd scalar (A) can be compatible with the ρ parameter, Br(b⃗sγ), Rb,Ab, (g-2)μ of the muon, Br(Υ⃗Aγ), and the direct search via the Yukawa process at CERN LEP. For its mass around 0.2 GeV, the muon (g-2)μ and Br(Υ⃗Aγ) data require tanβ to be about 1. Consequently, A can behave like a fermiophobic CP-odd scalar and predominantly decay into a γγ pair, which registers in detectors of high energy collider experiments as a single photon signature when the momentum of A is large. We compute the partial decay width of Z⃗AAA and the production rate of ff̅ →ZAA⃗Z+ “γγ,” f′f̅ →W±AA⃗W±+ “γγ,” and ff̅ →H+H-→W+W-AA⃗W+W-+ “γγ” at high energy colliders such as LEP, Fermilab Tevatron, CERN LHC, and future Linear Colliders. Other production mechanisms of a light A, such as gg⃗h⃗AA⃗ “γγ,” are also discussed.
    Physical review D: Particles and fields 08/2001; 64(5). DOI:10.1103/PhysRevD.64.055004 · 4.86 Impact Factor
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    ABSTRACT: A search for events with a photon pair arising from the decay of a Higgs boson produced in association with a fermion pair, is performed in 893 pb−1 of data recorded by the ALEPH detector at LEP at centre-of-mass energies up to 209 GeV. No excess of such events is found over the expected background. An upper limit is derived on the product of the e+e−→HZ cross section and the H→γγ branching fraction as a function of the Higgs boson mass. A fermiophobic Higgs boson produced with the Standard Model cross section is excluded at 95% confidence level for all masses below 105.4 GeV/c2.
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    ABSTRACT: A Higgs particle produced in association with a Z boson and decaying into two photons is searched for in the data collected by the L3 experiment at LEP. All possible decay modes of the Z boson are investigated. No signal is observed in 447.5 pb^-1 of data recorded at centre-of-mass energies up to 209 GeV. Limits on the branching fraction of the Higgs boson decay into two photons as a function of the Higgs mass are derived. A lower limit on the mass of a fermiophobic Higgs boson is set at 105.4 GeV at 95% confidence level.
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