Search for neutral and charged Higgs bosons in collisions at = 161 GeV and 172 GeV
DELPHI Collaboration, P. Abreu21 et al.
21LIP, IST, FCUL - Av. Elias Garcia, 14-1o, P-1000 Lisboa Codex, Portugal
Received: 18 August 1997
A search for neutral and charged Higgs bosons has been performed in the data collected by the DELPHI detector at centre-of-mass energies of 161 GeV and 172 GeV. The analysis assumes either the pair-production of charged Higgs bosons, ,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 into hadrons or a pair of leptons, and from the decay of into a pair of quarks or a pair have been considered. Lower limits at the 95% confidence level have been obtained on the Higgs boson masses. The limits are 66.2 GeV/c2 for h in the Standard Model, 59.5 GeV/c2 for h and 51.0 GeV/c2 for A in the minimal supersymmetric extension of the Standard Model with sensible assumptions on the model parameters and, using the 161 GeV data only, 51.5 GeV/c2 for in the general two-doublet scheme for branching fractions into hadrons below 0.8.