Speaker
Description
The PICO collaboration operates the world’s most sensitive bubble chambers for dark matter searches, setting some of the strongest constraints on spin-dependent WIMP–nucleon interactions. As the traditional WIMP parameter space becomes increasingly constrained, attention is turning toward light and exotic candidates, including fermionic and vector dark matter with absorptive (exothermic) kinematics. In our recent work, we reported the first limits on spin-dependent absorptive interactions using a non-relativistic effective field theory (NREFT) framework, extending sensitivity below 23 MeV/c² and setting world-leading bounds on spin-independent fermionic absorption. Building on this, we explore new directions involving spin-1 particles, in particular nuclear dark Compton scattering, a channel to which PICO detectors are uniquely sensitive. Together, these results underscore the versatility of bubble chambers in probing novel dark matter interaction channels and their continuing role at the forefront of low-mass dark matter searches.
