A search for neutral Higgs bosons has been performed using the full sample of Z 0 decays collected by the OPAL detector at LEP up to 1995. The data were taken at centre-of-mass energies between 88 GeV and 95 GeV and correspond to an integrated luminosity of approximately 160 pb 1. The present search addresses the processes Z 0 !H 0 Z and h 0 Z , where H 0 is the Higgs boson predicted by the Standard Model and h 0 the lightest neutral scalar Higgs boson predicted in the framework of the Minimal Supersymmetric Standard Model. For the virtual Z 0 boson, Z , the following decay c hannels are considered: Z ! , e + e and +. One candidate event

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The spectral functions of the vector current and the axial-vector current have been measured in hadronic τ decays using the OPAL detector at LEP. Within the framework of the Operator Product Expansion a simultaneous determination of the strong coupling constant α s , the non-perturbative operators of dimension 6 and 8 and of the gluon condensate has been performed. Different perturbative descriptions have been compared to the data. The Contour Improved Fixed Order Perturbation Theory gives α s (m 2 τ ) = 0.348±0.009 exp ±0.019 theo at the τ -mass scale and α s (m 2 Z ) = 0.1219±0.0010 exp ±0.0017 theo at the Z 0 -mass scale. The values obtained for α s (m 2 Z ) using Fixed Order Perturbation Theory or Renormalon Chain Resummation are 2.3 % and 4.1 % smaller, respectively. The 'running' of the strong coupling between s 0 ≃ 1.3 GeV 2 and s 0 = m 2 τ has been tested from direct fits to the integrated differential hadronic decay rate R τ (s 0 ). A test of the saturation of QCD sum rules at the τ -mass scale has been performed.

The proton and deuteron structure functions F p 2 and F d 2 are measured in inelastic muon scattering with an average beam energy of 470 GeV. The data were taken at Fermilab experiment E665 during 1991-92 using liquid hydrogen and deuterium targets. The F2 measurements are reported in the range 0:0008 < x < 0 : 6 and 0:2 < Q 2 < 75 GeV 2. These are the rst precise measurements of F2 in the low x and Q 2 range of the data. In the high x range of the data where they overlap in x and Q 2 with the measurements from NMC, the two measurements are in agreement. The E665 data also overlap in x with the HERA data, and there is a smooth connection in Q 2 between the two data sets. At high Q 2 the E665 measurements are consistent with QCDevolved leading twist structure function models. The data are qualitatively described 2 by structure function models incorporating the hadronic nature of the photon at low Q 2. The Q 2 and the W dependence of the data measure the transition in the nature of the photon between a point-like probe at high Q 2 and a hadronic object at low Q 2 .

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