XENON100 Dark Matter Results from a Combination of 477 Live Days

We report on WIMP search results of the XENON100 experiment, combining three runs summing up to 477 live days from January 2010 to January 2014. Data from the first two runs were already published. A blind analysis was applied to the last run recorded between April 2013 and January 2014 prior to combining the results. The ultralow electromagnetic background of the experiment, ∼5 × 10⁻³ events (keV_ee × kg × day)) before electronic recoil rejection, together with the increased exposure of 48 kg × yr, improves the sensitivity. A profile likelihood analysis using an energy range of f (6.6–43.3) keV_nr sets a limit on the elastic, spin-independent WIMP-nucleon scattering cross section for WIMP masses above e 8 GeV=c², with a minimum of 1.1 × 10⁻⁴⁵ cm² at 50 GeV / c² and 90% confidence level. We also report updated constraints on the elastic, spin-dependent WIMP-nucleon cross sections obtained with the same data. We set upper limits on the WIMP-neutron (proton) cross section with a minimum of 2.0 × 10⁻⁴⁰ cm² (52 × 10⁻⁴⁰ cm²) at a WIMP mass of 50 GeV / c², at 90% confidence level.