Angular analysis of muon pair production around the Z peak                     
  
   Data on muon pair production obtained by the OPAL collaboration at and      
   around the Z peak are analysed. Small angular mismatches between the        
   directions of the two muons are used to estimate the effects of initial     
   state photon radiation and initial-final state radiation interference on    
   the forward-backward asymmetry of muon pair production and its              
   dependence on the invariant mass of the pair.                               
  
 Parallel session :5                   
 Plenary  session :6a