Freiburg 2008 – wissenschaftliches Programm

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T: Fachverband Teilchenphysik

T 89: Niederenergie-Neutrinophysik und Suche nach Dunkler Materie IV

T 89.3: Vortrag

Freitag, 7. März 2008, 14:30–14:45, KGII-HS 2004

Indirect dark matter search with the balloon-borne PEBS detector. — •Henning Gast — I. Physikalisches Institut B, RWTH Aachen

Cosmic-ray positrons may contribute to solving the puzzle of the nature of dark matter, in combination with other approaches. For example, pairwise annihilation of neutralinos, predicted by supersymmetric extensions to the standard model of particle physics, may leave a distinct feature in the cosmic-ray positron spectrum.

As the available data are limited both in terms of statistics and energy range, we are developing a balloon-borne detector (PEBS) with a large acceptance of 4000 cm² sr. A superconducting magnet creating a field of 0.8 T and a tracking device consisting of scintillating fibers of 250 µ m diameter with silicon photomultiplier readout will allow rigidity and charge determination up to O(100 GeV). The dominant proton background is suppressed by the combination of an electromagnetic calorimeter and a transition radiation detector consisting of fleece layers interspersed with straw-tube proportional counters. The calorimeter uses a sandwich of tungsten and scintillating fibers that are again read out by silicon photomultipliers.

The design study, based on a detailed Geant4 simulation and testbeam measurements, will be presented along with an interpretation of the positron data in the context of supersymmetry.