Feasibility of slepton precision measurements at a muon collider
  Detectors at a high-energy muon collider must be protected from the decay products of beam muons by installing shielding material around the beam pipe. In this article, the impact of these blind detector regions on new-physics signatures with invisible final-state particles is shown by studying the production of sleptons, the superpartners of leptons. Special attention is given to large backgrounds from two-photon collisions. It is demonstrated how the influence of these backgrounds can be controlled by implementing suitable cuts or running at two different center-of-mass energies, thus permitting precision measurements of the mass and spin of the sleptons. However, these methods become ineffective for small mass differences between the sleptons and their decay products, and it will be difficult to analyze the slepton signal at a muon collider in this case. 
A. Freitas
hep-ph hep-ex