A search for low-mass WIMPs with EDELWEISS-II heat-and-ionization detectors

E. Armengaud (1) , C. Augier (2) , Alain Benoit (3) , L. Bergé (4) , T. Bergmann , J. Blümer , A. Broniatowski (4) , V. Brudanin , B. Censier (2) , M. Chapellier (4) , F. Charlieux (2) , F. Couëdo (4) , P. Coulter , G. A. Cox , J. Domange (4) , A. A. Drillien (4) , L. Dumoulin (4) , K. Eitel , D. Filosofov , N. Fourches (1) , J. Gascon (2) , G. Gerbier (1) , J. Gironnet (2) , M. Gros (1) , G. Heuermann , S. Henry , S. Hervé (1) , A. Juillard (2) , M. Kleifges , H. Kluck , V. Kozlov , H. Kraus , V. A. Kudryavtsev , Hélène Le Sueur (4) , P. Loaiza (5) , S. Marnieros (4) , A. Menshikov , X-F. Navick (1) , C. Nones (1) , E. Olivieri (4) , P. Pari , B. Paul (1) , M. Robinson , S. Rozov , V. Sanglard (2) , B. Schmidt , B. Siebenborn , D. Tcherniakhovski , A. S. Torrento-Coello (1) , L. Vagneron (2) , R. J. Walker (1) , M. Weber , E. Yakushev , X. Zhang

1 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers
2 IPNL - Institut de Physique Nucléaire de Lyon
3 NEEL - HELFA - Hélium : du fondamental aux applications
4 CSNSM - Centre de Sciences Nucléaires et de Sciences de la Matière
5 LSM - UMR 6417 - Laboratoire Souterrain de Modane

We report on a search for low-energy (E < 20 keV) WIMP-induced nuclear recoils using data collected in 2009 - 2010 by EDELWEISS from four germanium detectors equipped with thermal sensors and an electrode design (ID) which allows to efficiently reject several sources of background. Using an exposure of 113 kg.d, we find no evidence for an exponential distribution of low-energy nuclear recoils that could be attributed to WIMP elastic scattering. For WIMPs of mass 10 GeV, the observation of one event in the WIMP search region results in a 90% CL limit of 1.0 \times 10^-5 pb on the spin-independent WIMP-nucleon scattering cross-section, which constrains the parameter space associated with the findings reported by the CoGeNT, DAMA and CRESST experiments.

Domaines: Physique des Hautes Energies - Expérience [hep-ex]; Instrumentations et Détecteurs [physics.ins-det]

E. Armengaud, C. Augier, Alain Benoit, L. Bergé, T. Bergmann, et al.. A search for low-mass WIMPs with EDELWEISS-II heat-and-ionization detectors. Physical Review D, 2012, 86, pp.051701. ⟨10.1103/PhysRevD.86.051701⟩. ⟨in2p3-00716140⟩