are null to 90% If, as in searches for proton decay, the results continue to be null for experiments in the next several decades, as they have been for proton decay, at what point does the SUSY-neutralino space, or GUT axion, or other cold DM candidates, becomes constrained? Obviously a positive result would be strong evidence for SUSY/strings. SUSY helps the running coupling constants unify at 10^15 GEV, and the neutralino is stable, has the right mass and right predicted abundance after Big Bang to account for DM. The null result constrains the parameter space, but would the continued non-detection be a problem for XENON100 a problem for SUSY or string theory? My intuition is that all searches for DM, proton decay, SUSY @ LHC, magnetic monopoles, axions, Lorentz-violating Gamma ray bursts, will continue to be null. for a more detailed discussion http://resonaances.blogspot.com/2010/05/more-dark-entries.html original paper, arXiv:1005.0380 First Dark Matter Results from the XENON100 Experiment Authors: E. Aprile, K. Arisaka, F. Arneodo, A. Askin, L. Baudis, A. Behrens, E. Brown, J. M. R. Cardoso, B. Choi, D. B. Cline, S. Fattori, A. D. Ferella, K.-L. Giboni, K. Hugenberg, A. Kish, C. W. Lam, J. Lamblin, R. F. Lang, K. E. Lim, J. A. M. Lopes, T. Marrodán Undagoitia, Y. Mei, A. J. Melgarejo Fernandez, K. Ni, U. Oberlack, S. E. A. Orrigo, E. Pantic, G. Plante, A. C. C. Ribeiro, R. Santorelli, J. M. F. dos Santos, M. Schumann, P. Shagin, A. Teymourian, D. Thers, E. Tziaferi, H. Wang, C. Weinheimer (XENON100 Collaboration) (Submitted on 3 May 2010) Abstract: The XENON100 experiment, in operation at the Laboratori Nazionali del Gran Sasso in Italy, is designed to search for dark matter WIMPs scattering off 62 kg of liquid xenon in an ultra-low background dual-phase time projection chamber. In this letter, we present first dark matter results from the analysis of 11.17 live days of non-blind data, acquired in October and November 2009. In the selected fiducial target of 40 kg, and within the pre-defined signal region, we observe no events and hence exclude spin-independent WIMP-nucleon elastic scattering cross-sections above 3 x 10^-44 cm^2 for 50 GeV/c^2 WIMPs at 90% confidence level. Below 20 GeV/c^2, this result challenges the interpretation of the CoGeNT or DAMA signals as being due to spin-independent, elastic, light mass WIMP interactions.