Decay mode independent search for a light Higgs boson and new scalars

Using data from e+e− collisions collected with the OPAL detector during the 1990 LEP run, a search was mode for a low mass Higgs boson (H0) with arbitrary decay mode. The existence of a minimal standard model H0 with mass in the range 0 ⩽ mH ⩽ 11.3 GeV/c2 is excluded at the 95% confidence level for all possible decay modes of the H0. Limits on the production of Higgs bosons predicted by the minimal supersymmetric standard model and new scalar particles that couple to the Z0 are presented as a function of the scalar mass.