We present constraints on the annihilation cross section of weakly interacting massive particles dark matter based on the joint statistical analysis of four dwarf galaxies with VERITAS. These results are derived from an optimized photon weighting statistical technique that improves on standard imaging atmospheric Cherenkov telescope (IACT) analyses by utilizing the spectral and spatial properties of individual photon events. We report on the results of ∼230 hours of observations of five dwarf galaxies and the joint statistical analysis of four of the dwarf galaxies. We find no evidence of gamma-ray emission from any individual dwarf nor in the joint analysis. The derived upper limit on the dark matter annihilation cross section from the joint analysis is 1.35×10-23 cm3 s-1 at 1 TeV for the bottom quark (bb) final state, 2.85×10-24 cm3 s-1 at 1 TeV for the tau lepton (τ+τ-) final state and 1.32×10-25 cm3 s-1 at 1 TeV for the gauge boson (γγ) final state.
Bibliographical noteFunding Information:
This research is supported by grants from the U.S. Department of Energy Office of Science, the U.S. National Science Foundation and the Smithsonian Institution, and by Natural Sciences and Engineering Research Council of Canada (NSERC) in Canada.