Results from a Search for Light-Mass Dark Matter with a<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>p</mml:mi></mml:math>-Type Point Contact Germanium Detector
C.E. AalsethPacific Northwest National Laboratory, Richland, Washington 99352, USAP. S. BarbeauKavli Institute for Cosmological Physics and Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USAN. S. BowdenLawrence Livermore National Laboratory, Livermore, California 94550, USABelkis Cabrera-PalmerSandia National Laboratories, Livermore, California 94550, USAJ. ColaresiJ. I. CollarKavli Institute for Cosmological Physics and Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USAS. DazeleyLawrence Livermore National Laboratory, Livermore, California 94550, USAP. De LurgioArgonne National Laboratory, Argonne, Illinois 60439, USAJ. FastPacific Northwest National Laboratory, Richland, Washington 99352, USANicole D. FieldsUniversity of ChicagoC. GreenbergKavli Institute for Cosmological Physics and Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USAT. W. HossbachKavli Institute for Cosmological Physics and Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USAMartin E. KeillorPacific Northwest National Laboratory, Richland, Washington 99352, USAJ. D. KephartPacific Northwest National Laboratory, Richland, Washington 99352, USAM. G. MarinoCenter for Experimental Nuclear Physics and Astrophysics and Department of Physics, University of Washington, Seattle, Washington 98195, USAH.S. MileyPacific Northwest National Laboratory, Richland, Washington 99352, USAM. L. MillerCenter for Experimental Nuclear Physics and Astrophysics and Department of Physics, University of Washington, Seattle, Washington 98195, USAJ. L. OrrellPacific Northwest National Laboratory, Richland, Washington 99352, USAD. C. RadfordOak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USAD. ReynaSandia National Laboratories, Livermore, California 94550, USAO. TenchT.D. Van WechelCenter for Experimental Nuclear Physics and Astrophysics and Department of Physics, University of Washington, Seattle, Washington 98195, USAJ. F. WilkersonCenter for Experimental Nuclear Physics and Astrophysics and Department of Physics, University of Washington, Seattle, Washington 98195, USAK. M. Yocum
2011en
ABI
Abstract
We report on several features in the energy spectrum from an ultralow-noise germanium detector operated deep underground. By implementing a new technique able to reject surface events, a number of cosmogenic peaks can be observed for the first time. We discuss an irreducible excess of bulklike events below 3 keV in ionization energy. These could be caused by unknown backgrounds, but also dark matter interactions consistent with DAMA/LIBRA. It is not yet possible to determine their origin. Improved constraints are placed on a cosmological origin for the DAMA/LIBRA effect.
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Citations and references
Cited by 50 references