2021 Impact factor 4.991
Particles and Fields

Eur. Phys. J. C 18, 425-445
DOI: 10.1007/s100520100544

Two Higgs Doublet Model and model independent interpretation of neutral Higgs boson searches

The OPAL Collaboration G. Abbiendi and et al.

Dipartimento di Fisica dell' Università di Bologna and INFN, 40126 Bologna, Italy

(Received: 11 July 2000 / Published online: 21 December 2000 - © Springer-Verlag 2000)

Searches for the neutral Higgs bosons h0 and A0 are used to obtain limits on the Type II Two Higgs Doublet Model (2HDM(II)) with no CP-violation in the Higgs sector and no additional particles besides the five Higgs bosons. The analysis combines approximately 170 pb-1 of data collected with the OPAL detector at $\sqrt{s} \approx 189$ GeV with previous runs at $\sqrt{s} \approx m_{Z}$ and $\sqrt{s} \approx 183$ GeV. The searches are sensitive to the h0, $\mathrm{A}^{0}\rightarrow\mathrm{q}\bar{\mathrm{q}}$, gg, $\tau^+\tau^-$ and $\mathrm{h}^{0}\rightarrow\mathrm{A}^{0}\mathrm{A}^{0}$ decay modes of the Higgs bosons. For the first time, the 2HDM(II) parameter space is explored in a detailed scan, and new flavour independent analyses are applied to examine regions in which the neutral Higgs bosons decay predominantly into light quarks or gluons. Model-independent limits are also given.

© Società Italiana di Fisica, Springer-Verlag 2001