First background-free limit from a directional dark matter experiment: Results from a fully fiducialised DRIFT detector.

Autor: Battat, J.B.R., Brack, J., Daw, E., Dorofeev, A., Ezeribe, A.C., Gauvreau, J.-L., Gold, M., Harton, J.L., Landers, J.M., Law, E., Lee, E.R., Loomba, D., Lumnah, A., Matthews, J.A.J., Miller, E.H., Monte, A., Mouton, F., Murphy, A.StJ., Paling, S.M., Phan, N.
Zdroj: Physics of the Dark Universe; Sep2015, Vol. 9, p1-7, 7p
Abstrakt: The addition of O 2 to gas mixtures in time projection chambers containing CS 2 has recently been shown to produce multiple negative ions that travel at slightly different velocities. This allows a measurement of the absolute position of ionising events in the z (drift) direction. In this work, we apply the z -fiducialisation technique to a directional dark matter search. We present results from a 46.3 live-day source-free exposure of the DRIFT-IId detector run in this new mode. With full-volume fiducialisation, we have achieved the first background-free operation of a directional detector. The resulting exclusion curve for spin-dependent WIMP-proton interactions reaches 1.1 pb at 100 GeV/c 2 , a factor of 2 better than our previous work. We describe the automated analysis used here, and argue that detector upgrades, implemented after the acquisition of these data, will bring an additional factor of ≳ 3 improvement in the near future. [ABSTRACT FROM AUTHOR]
Databáze: Supplemental Index
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