Erratum: Low-mass dark matter search using ionization signals in XENON100 (Physical Review D (2016) 94 (092001) DOI: 10.1103/PhysRevD.94.092001)

In Fig. 5 of our original article, we compared measurements and predictions of the charge yield Qy. In that figure, the LUX points were misrepresented, and therefore we present here in Fig. 1 the corrected points from Ref. [1]. (Figure Presented). This has no impact on the presented results or conclusions

Excess electronic recoil events in XENON1T

We report results from searches for new physics with low-energy electronic recoil data recorded with the XENON1T detector. With an exposure of 0.65 tonne-years and an unprecedentedly low background rate of 76\ub12stat\u2009\u2009events/(tonne 7year 7keV) between 1 and 30 keV, the data enable one of the most sensitive searches for solar axions, an enhanced neutrino magnetic moment using solar neutrinos, and bosonic dark matter. An excess over known backgrounds is observed at low energies and most prominent between 2 and 3 keV. The solar axion model has a 3.4\u3c3 significance, and a three-dimensional 90% confidence surface is reported for axion couplings to electrons, photons, and nucleons. This surface is inscribed in the cuboid defined by gae<3.8 710-12, gaeganeff<4.8 710-18, and gaega\u3b3<7.7 710-22\u2009\u2009GeV-1, and excludes either gae=0 or gaega\u3b3=gaeganeff=0. The neutrino magnetic moment signal is similarly favored over background at 3.2\u3c3, and a confidence interval of \u3bc\u3bd 08(1.4,2.9) 710-11\u2009\u2009\u3bcB (90% C.L.) is reported. Both results are in strong tension with stellar constraints. The excess can also be explained by \u3b2 decays of tritium at 3.2\u3c3 significance with a corresponding tritium concentration in xenon of (6.2\ub12.0) 710-25\u2009\u2009mol/mol. Such a trace amount can neither be confirmed nor excluded with current knowledge of its production and reduction mechanisms. The significances of the solar axion and neutrino magnetic moment hypotheses are decreased to 2.0\u3c3 and 0.9\u3c3, respectively, if an unconstrained tritium component is included in the fitting. With respect to bosonic dark matter, the excess favors a monoenergetic peak at (2.3\ub10.2)\u2009\u2009keV (68% C.L.) with a 3.0\u3c3 global (4.0\u3c3 local) significance over background. This analysis sets the most restrictive direct constraints to date on pseudoscalar and vector bosonic dark matter for most masses between 1 and 210\u2009\u2009keV/c2. We also consider the possibility that Ar37 may be present in the detector, yielding a 2.82 keV peak from electron capture. Contrary to tritium, the Ar37 concentration can be tightly constrained and is found to be negligible