Hadronic Parity Violation

Barry Holstein
University of Massachusetts, Amherst

The subject of parity violation in strong and electromagnetic interactions 
due to the presence of the weak force has been studied now for more than 
fifty years.  However, despite a great deal of experimental and theoretical 
effort in this regard, our understanding of such effects remains cloudy.  
There are a number of reasons for this.  One is that in contrast to the 
parity-conserving situation, where there are only two fundamental constants 
(scattering lengths) which describe the NN interaction, in the 
parity-violating case there are five.  Also, for the past thirty years 
nearly all such processes have been described within the model-dependent 
DDH meson-exchange model.  Recently effective field theoretic techniques 
have been developed in order to ameliorate the latter problem and a series 
of high precision experiments has been undertaken in order to address the 
former.   A review of both the experimental and theoretical situations 
will be presented.