Muon-induced background in the EDELWEISS dark matter search
  A dedicated analysis of the muon-induced background in the EDELWEISS dark
matter search has been performed on a data set acquired in 2009 and 2010. The
total muon flux underground in the Laboratoire Souterrain de Modane (LSM) was
measured to be $\Phi_{\mu}=(5.4\pm 0.2 ^{+0.5}_{-0.9})$\,muons/m$^2$/d. The
modular design of the muon-veto system allows the reconstruction of the muon
trajectory and hence the determination of the angular dependent muon flux in
LSM. The results are in good agreement with both MC simulations and earlier
measurements. Synchronization of the muon-veto system with the phonon and
ionization signals of the Ge detector array allowed identification of
muon-induced events. Rates for all muon-induced events $\Gamma^{\mu}=(0.172 \pm
0.012)\, \rm{evts}/(\rm{kg \cdot d})$ and of WIMP-like events $\Gamma^{\mu-n} =
0.008^{+0.005}_{-0.004}\, \rm{evts}/(\rm{kg \cdot d})$ were extracted. After
vetoing, the remaining rate of accepted muon-induced neutrons in the
EDELWEISS-II dark matter search was determined to be $\Gamma^{\mu-n}_{\rm
irred} < 6\cdot 10^{-4} \, \rm{evts}/(\rm{kg \cdot d})$ at 90%\,C.L. Based on
these results, the muon-induced background expectation for an anticipated
exposure of 3000\,\kgd\ for EDELWEISS-3 is $N^{\mu-n}_{3000 kg\cdot d} < 0.6$
events.
