Dark matter search results from the commissioning run of PandaX-II

Abstract

We present the results of a search for WIMPs from the commissioning run of the PandaX-II experiment located at the China Jinping underground Laboratory. A WIMP search data set with an exposure of 306×19.1 kg-day was taken, while its dominant 85 Kr background was used as the electron recoil calibration. No WIMP candidates are identified, and a 90% upper limit is set on the spin-independent elastic WIMP-nucleon cross section with a lowest excluded cross section of 2.97×10 −45 cm 2 at a WIMP mass of 44.7 GeV/c 2 .PACS numbers: 95.35.+d, 29.40.-n, 95.55.Vj

A singlet doublet dark matter model with radiative neutrino masses

“…On the resonance, annihilation is very efficient and the couplings and direct detection cross section must be very small. As expected for singlet-doublet scalar dark matter alone [32,33], most of the parameter points are now excluded by PandaX [57,58] (dashed curve) and XENON1T [59] (full curve). Furthermore, they obviously cannot explain the neutrino masses.…”

Constraining Dark Matter Models with a Light Mediator at the PandaX-II Experiment

“…Both signals are detected in one event by two arrays of photomultiplier tubes (PMTs), located in the top and bottom of the TPC. More detailed descriptions of the PandaX-II experiment can be found in [20][21][22].…”

The China Jinping Underground Laboratory and Its Early Science

“…On the basis of a profile likelihood analysis of all data, an exclusion limit on the spin-independent χN cross section was obtained (Figure 9b). The most stringent limit, 2.5 × 10 −46 cm 2 at a WIMP mass of 40 GeV/c 2 , represents an improvement of more than a factor of 10 from the limit in Reference [49]. In the high-WIMP-mass region, the bounds improve by more than a factor of two over the previous most stringent limit from LUX [56].…”

“…The upgrade to PandaX-II ( Figure 7b) includes a new low-background steel inner vessel, an increased liquid xenon target mass of 580 kg, and a total of 110 3-inch-diameter PMTs. An additional 48 1-inch-diameter PMTs serve as an active veto in the optically isolated 4-cm liquid xenon region surrounding the outer circumference of the TPC, providing extra power for background rejection [49].…”

“…The data taking concluded with the identification of a strong 85 Kr background. The analysis of this data set has been published [49]. No WIMP candidates were identified, and a 90% upper limit comparable to the 225-day limit from XENON100 [45] was set.…”