New XENON articles...

The unprecedented low background and large 1 ton x year exposure of XENON1T data allowed us to publish two more papers placing world-leading constraints on dark matter interactions:

First results on the scalar WIMP-pion coupling, using the XENON1T experiment
E. Aprile et al. (XENON Collaboration)
Phys. Rev. Lett. 122, 071301 (2019), arXiv:1811.12482

This article presents the world's first results on the coupling of WIMP dark matter with virtual pions. These are constantly exchanged between the nucleons in a xenon nucleus. These pion-exchange currents can be coherently enhanced by the total number of nucleons, and therefore may dominate in scenarios where spin-independent WIMP-nucleon interactions are suppressed. Using the signal model of this new WIMP-pion channel, no significant excess is found in the XENON1T data, leading to an upper limit cross section of 6.4 x 10^-46 cm² (90 % confidence level) at 30 GeV/c2 WIMP mass.

Constraining the spin-dependent WIMP-nucleon cross sections with XENON1T
E. Aprile et al. (XENON Collaboration)
Phys. Rev. Lett. 122, 141301 (2019), arXiv:1902.03234
The article has been chosen as an "Editor's Suggestion" by PRL.

Using the full 1 txy exposure of XENON1T, we report the first experimental results on spin-dependent elastic WIMP-nucleon scattering. This channel assumes that the WIMP couples to unpaired nucleons, present in the xenon target at ~50% due to the presence of ¹²⁹Xe and ¹³¹Xe. No significant signal excess was observed and exclusion limits were placed on the WIMP-neutron and WIMP-proton interactions. This yields the most stringent constraint to date on the WIMP-neutron cross section, with a minimum of 6.3 x 10^-42 cm² at 30 GeV/c2 and 90% confidence level. The results are compared with those from collider searches and used to exclude new parameter space in an isoscalar theory with an axial-vector mediator.