RESUMO
Imaging Atmospheric Cherenkov telescope (IACT) searches for dark matter often perform observations in "wobble mode," i.e., simultaneously collecting data from the signal region and from a corresponding background control region. This observation strategy is possibly compromised in scenarios where dark matter annihilates to long-lived mediators that can traverse astrophysical distances before decaying to produce the gamma rays observed by the IACTs. In this Letter, we show that this challenge comes with several interesting features and opportunities: in addition to signal contamination in the background control region, the gamma-ray spectrum changes with the observing direction angle and typically exhibits a hard excess at high energies. Such features represent a significant departure from the canonical picture and offer novel handles to identify a dark matter signal and to extract underlying dark matter parameters.
RESUMO
Future neutron-antineutron (n-n[over ¯]) oscillation experiments, such as at the European Spallation Source and the Deep Underground Neutrino Experiment, aim to find first evidence of baryon number violation. We investigate implications of an improved n-n[over ¯] oscillation search for baryogenesis via interactions of n-n[over ¯] mediators, parametrized by an effective field theory (EFT). We find that even in a minimal EFT setup there is overlap between the parameter space probed by n-n[over ¯] oscillation and the region that can realize the observed baryon asymmetry of the Universe. The mass scales of exotic new particles are in the tera-electron-volt-peta-electron-volt regime, inaccessible at the LHC or its envisioned upgrades. Given the innumerable high energy theories that can match, or resemble, the minimal EFT that we discuss, future n-n[over ¯] oscillation experiments could probe many viable theories of baryogenesis beyond the reach of other experiments.
