Eur. Phys. J. C 19, 535-546
DOI: 10.1007/s100520100631

Neutral MSSM Higgs-boson production at e⁺e^- colliders in the Feynman-diagrammatic approach

S. Heinemeyer¹, W. Hollik², J. Rosiek^{3, 4} and G. Weiglein<sup>5

1</sup>  HET, Physics Department, Brookhaven Natl. Lab., Upton, NY 11973, USA
²  Institut für Theoretische Physik, Universität Karlsruhe, 76128 Karlsruhe, Germany
³  Physik-Department, Technische Universität München, 85747 Garching, Germany
⁴  Institute of Theoretical Physics, Warsaw University, 00681 Warsaw, Poland
⁵  CERN, TH Division, 1211 Geneva 23, Switzerland

Sven.Heinemeyer@bnl.gov
Wolfgang.Hollik@physik.uni-karlsruhe.de
Janusz.Rosiek@ph.tum.de
Georg.Weiglein@cern.ch

(Received: 7 February 2001 / Published online: 23 March 2001 -© Springer-Verlag 2001)

Abstract
We calculate the cross sections for the neutral Higgs-boson production at e⁺e^- colliders in the Minimal Supersymmetric Standard Model (MSSM) using the Feynman-diagrammatic approach and the on-shell renormalization scheme. We incorporate the Higgs-boson propagator corrections, evaluated up to two-loop order, into the prediction of the cross sections for the Higgs-boson production mechanism . The propagator corrections consist of the full one-loop contribution, including the effects of non-vanishing external momentum, and at the two-loop level of the dominant corrections of and further sub-dominant contributions. The results are supplemented with the complete set of one-loop vertex and box corrections. The effects of the two-loop propagator corrections are investigated in detail. We briefly discuss also the effect of the box contributions for high . We compare our results with the case where only the corrections to the effective mixing angle, evaluated within the renormalization-group-improved one-loop Effective Potential approach, are taken into account. We find agreement better than 10% for LEP2 energies and deviations larger than 20% for GeV.

© Società Italiana di Fisica, Springer-Verlag 2001