Hidden variable problem for a family of continuously many spin 1   measurements
  We study a continuous set of spin 1 measurements and show that for a special family of measurements parametrized by a single variable $\theta$ the possibility of hidden-variable description is a discontinuous property. 
Pawel Kurzynski, Akihito Soeda, Bartlomiej Bzdega, Dagomir   Kaszlikowski
quant-ph