# Muon-induced background in the EDELWEISS dark matter search

4 CSNSM INSTR
CSNSM - Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse
5 ElecLab - Electronique
NEEL - Institut Néel
6 CSNSM PS1
CSNSM - Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse, CSNSM - Centre de Sciences Nucléaires et de Sciences de la Matière
8 Cryo - Cryogénie
NEEL - Institut Néel
9 MANOIR - Matière noire
IP2I Lyon - Institut de Physique des 2 Infinis de Lyon
Abstract : 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.
Document type :
Journal articles
Domain :

http://hal.in2p3.fr/in2p3-00796374
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Submitted on : Monday, March 4, 2013 - 8:01:13 AM
Last modification on : Sunday, June 26, 2022 - 11:58:23 AM

### Citation

B. Schmidt, E. Armengaud, C. Augier, Alain Benoit, L. Bergé, et al.. Muon-induced background in the EDELWEISS dark matter search. Astroparticle Physics, Elsevier, 2013, 44, pp.28-39. ⟨10.1016/j.astropartphys.2013.01.014⟩. ⟨in2p3-00796374⟩

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