Higgss-channel production ine + e − collisions below theW + W − threshold

Abstract

The cross section for direct neutral Higgs production in the reaction\(e^ + e^ - \to H^0 \to f \bar f\) is calculated in theECM energy range of 40 to 160 GeV and compared to the corresponding Electro-Weak (EW) process\(e^ + e^ - \to (Z,\gamma ) \to f \bar f\). Neglecting radiation effects, a signal of the order of 10−4 to 10−3 over the EW can be expected outside theZ0 region for the Minimal Standard Model Higgs in its decay to a\(b\bar b\) state. For\(M_H > \sqrt s - M_Z \), thes-channel Higgs formation can surpass the Bjorken Bremsstrahlung process and thus may afford at LEP 2 a realistic search method for high mass, say ≧100 GeV Higgs, given enough luminosity. For a non-Standard Model Higgs, in some cases, significantly higher signals are expected. The effects of initial state radiation and-machine energy resolution are evaluated and the gain in using longitudinal polarized electron beams is discussed.