Eur. Phys. J. C 19, 463-469
DOI: 10.1007/s100520100585

The light Higgs window in the 2HDM at GigaZ

M. Krawczyk¹, P. Mättig² and J. Zochowski<sup>3

1</sup>  Institute of Theoretical Physics, University of Warsaw, Warsaw, 00-681, Poland
²  Weizmann Institute, Rehovot, Israel
³  Faculty of Physics, Bialystok University, Bialystok, Poland

(Received: 18 September 2000 / Revised version: 22 December 2000 / Published online: 15 March 2001 -© Springer-Verlag 2001)

Abstract
The sensitivity to a light Higgs boson in the general 2HDM (II), with a mass below 40 GeV, is estimated for a future e⁺e^- Linear Collider operating with a very high luminosity at the Z peak (GigaZ). We consider possible Higgs boson production via the Bjorken process, the (hA) pair production, the Yukawa process , and the decay . Although the discovery potential is considerably extended compared to the current sensitivities, mainly from LEP, the existence of a h or A even with a mass of a few GeV cannot be excluded with two billion Z decays. The need to study the very light Higgs scenario at a e⁺e^- Linear Collider running at several hundred GeV and the LHC is emphasized.

© Società Italiana di Fisica, Springer-Verlag 2001