J. H. Hinnefeld

Publications (2)7.37 Total impact

• Source

  Available from: Ilan Levine

  Article: Improved limits on spin-dependent WIMP-proton interactions from a two liter CF3I bubble chamber.

  E Behnke, J Behnke, S J Brice, D Broemmelsiek, J I Collar, P S Cooper, M Crisler, C E Dahl, D Fustin, J Hall, J H Hinnefeld, M Hu, I Levine, E Ramberg, T Shepherd, A Sonnenschein, M Szydagis
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  ABSTRACT: Data from the operation of a bubble chamber filled with 3.5 kg of CF3I in a shallow underground site are reported. An analysis of ultrasound signals accompanying bubble nucleations confirms that alpha decays generate a significantly louder acoustic emission than single nuclear recoils, leading to an efficient background discrimination. Three dark matter candidate events were observed during an effective exposure of 28.1  kg  day, consistent with a neutron background. This observation provides strong direct detection constraints on weakly interacting massive particle (WIMP)-proton spin-dependent scattering for WIMP masses >20  GeV/c2.
  Physical Review Letters 01/2011; 106(2):021303. · 7.37 Impact Factor
• Source

  Available from: Ilan Levine

  Article: Improved Limits on Spin-Dependent WIMP-Proton Interactions from a Two Liter CF$_3$I Bubble Chamber

  E. Behnke, J. Behnke, S. J. Brice, D. Broemmelsiek, J. I. Collar, P. S. Cooper, M. Crisler, C. E. Dahl, D. Fustin, J Hall, J. H. Hinnefeld, M. Hu, I Levine, E. Ramberg, T. Shepherd, A. Sonnenschein, M. Szydagis
  [show abstract] [hide abstract]
  ABSTRACT: Data from the operation of a bubble chamber filled with 3.5 kg of CF$_{3}$I in a shallow underground site are reported. An analysis of ultrasound signals accompanying bubble nucleations confirms that alpha decays generate a significantly louder acoustic emission than single nuclear recoils, leading to an efficient background discrimination. Three dark matter candidate events were observed during an effective exposure of 28.1 kg-day, consistent with a neutron background. This observation provides the strongest direct detection constraint to date on WIMP-proton spin-dependent scattering for WIMP masses $>20$ GeV/c$^{2}$.
  08/2010;