Speaker
Description
The PICO collaboration uses bubble chambers filled with superheated C3F8 as a target for dark matter detection. PICO-60, with a threshold of 2.45 keV, set the most stringent direct-detection constraint to date on the weakly interacting massive particle (WIMP)-proton spin-dependent cross section at 3.2 × 10−41cm2 for a 25 GeV WIMP [Phys. Rev. D100 022001 (2019)]. Its successor PICO-40L employs a “right-side-up” configuration of the de- tector, thereby eliminating the need for the previously used buffer liquid and enhancing its background rejection capability. PICO-40L also serves as a prototype for another next gener- ation ton-scale chamber PICO-500 which will further explore the WIMP-nucleon parameter space. The commissioning of PICO-40L is nearly complete. Its upcoming run is expected to considerably improve on the previous limit.
