Direct WIMP searches with XENON100 and XENON1T

Abstract

Abstract. The XENON100 experiment is the second phase of the XENON direct Dark Matter search program. It consists of an ultra-low background double phase (liquid-gas) xenon filled time projection chamber with a total mass of 161 kg (62 in the target region and 99 in the active shield), installed at the Laboratori Nazionali del Gran Sasso (LNGS). Here the results from the 224.6 live days of data taken between March 2011 and April 2012 are reported. The experiment set one of the most stringent limits on the WIMPnucleon spin-independent cross section to date (2 × 10 −45 cm 2 for a 55 Gev/c 2 WIMP mass at 90 % confidence level) and the most stringent on the spin-dependent WIMPneutron interaction (3.5 × 10 −40 for a 45 GeV/c 2 WIMP mass). With the same dataset, XENON100 excludes also solar axion coupling to electrons at g Ae > 7.7 × 10 −12 for a mass of m Axion <1 keV/c 2 and galactic axion couplings by g Ae > 1 × 10 −12 at a mass range of m Axion = 5 − 10 keV/c 2 (both 90 % C.L.). Moreover an absolute spectral comparison between simulated and measured nuclear recoil distributions of light and charge signals from a 241 AmBe source demonstrates a high level of detector and systematics understanding. Finally, the third generation of the XENON experiments, XENON1T, is the first tonne scale direct WIMP search experiment currently under construction. The commissioning phase of XENON1T is expected to start in early 2015 followed, a few months after, by the first science run. The experiment will reach sensitivities on the WIMP-nucleon spin-independent cross section down to 2 ×10 −47 cm 2 after two years of data taking.

Production regimes for Self-Interacting Dark Matter

“…Concerning direct detection, it is known that the m A 1 GeV region is still below current experimental reach (see figure 8) but future experiments (e.g. Xenon1T [92] or LZ [93]) will be able to probe this region. For sub-GeV DM masses, there would be in principle constraints from electron-recoil analysis [94][95][96][97][98], but here they are irrelevant anyway, because both A and η particles are only feebly coupled to electrons.…”