Likelihood Approach to the First Dark Matter Results from XENON100
Abstract
Many experiments that aim at the direct detection of Dark Matter are able to distinguish a dominant background from the expected feeble signals, based on some measured discrimination parameter. We develop a statistical model for such experiments using the Profile Likelihood ratio as a test statistic in a frequentist approach. We take data from calibrations as control measurements for signal and background, and the method allows the inclusion of data from Monte Carlo simulations. Systematic detector uncertainties, such as uncertainties in the energy scale, as well as astrophysical uncertainties, are included in the model. The statistical model can be used to either set an exclusion limit or to make a discovery claim, and the results are derived with a proper treatment of statistical and systematic uncertainties. We apply the model to the first data release of the XENON100 experiment, which allows to extract additional information from the data, and place stronger limits on the spin-independent elastic WIMP-nucleon scattering cross-section. In particular, we derive a single limit, including all relevant systematic uncertainties, with a minimum of 2.4x10^-44 cm^2 for WIMPs with a mass of 50 GeV/c^2.
Keywords
Cite
@article{arxiv.1103.0303,
title = {Likelihood Approach to the First Dark Matter Results from XENON100},
author = {XENON100 Collaboration and E. Aprile and K. Arisaka and F. Arneodo and A. Askin and L. Baudis and A. Behrens and K. Bokeloh and E. Brown and T. Bruch and J. M. R. Cardoso and B. Choi and D. Cline and E. Duchovni and S. Fattori and A. D. Ferella and K. -L. Giboni and E. Gross and A. Kish and C. W. Lam and J. Lamblin and R. F. Lang and K. E. Lim and S. Lindemann and M. Lindner and J. A. M. Lopes and T. Marrodán Undagoitia and Y. Mei and A. J. Melgarejo Fernandez and K. Ni and U. Oberlack and S. E. A. Orrigo and E. Pantic and G. Plante and A. C. C. Ribeiro and R. Santorelli and J. M. F. dos Santos and M. Schumann and P. Shagin and A. Teymourian and D. Thers and E. Tziaferi and O. Vitells and H. Wang and M. Weber and C. Weinheimer},
journal= {arXiv preprint arXiv:1103.0303},
year = {2011}
}
Comments
8 pages, 6 figures, matches accepted version