Some problems in plasma suppression of beam-beam interactions at muon   colliders
  The idea of plasma suppression of beam-beam effects at muon colliders is discussed. It is shown that one should take into account collisions in the plasma that were ignored before. Rough estimates show that this effect leads to a fast ``recovery'' of the beam magnetic field. For beam parameters characteristic for muon colliders the suppression of the magnetic component of the beam field (1/2 of the total force) is almost absent. It is also shown that the presence of the dense plasma (Li jet) at the interaction point leads to enormous hadronic background (due to photo-nuclear reactions) in the detector, about 10^{7} particles per crossing at large angles which creates serious problems for experimentation. 
Valery Telnov (Budker Institute of Nuclear Physics)