Search for Ultraheavy Dark Matter from Observations of Dwarf Spheroidal Galaxies with VERITAS
A. Acharyya, A. Archer, P. Bangale, J. T. Bartkoske, P. Batista, Matthew Baumgart, W. Benbow, J. H. Buckley, A. Falcone, Q. Feng, J. P. Finley, G. M. Foote, L. Fortson, A. Furniss, G. Gallagher, W. Hanlon, O. Hervet, John Hoang, J. Holder, T. B. Humensky, W. Jin, P. Kaaret, M. Kertzman, M. Kherlakian, D. Kieda, T. K. Kleiner, N. Korzoun, F. Krennrich, M. J. Lang, M. Lundy, G. Maier, C.E. McGrath, P. Moriarty, S. O’Brien, R. A. Ong, K. Pfrang, M. Pohl, E. Pueschel, J. Quinn, K. Ragan, P. T. Reynolds, E. Roache, Nicholas L. Rodd, J. Ryan, I. Sadeh, L. Saha, M. Santander, G. H. Sembroski, R. Shang, M. Splettstoesser, D. Tak, J. V. Tucci, V. V. Vassiliev, D. A. Williams
Abstract
Abstract Dark matter is a key piece of the current cosmological scenario, with weakly interacting massive particles (WIMPs) a leading dark matter candidate. WIMPs have not been detected in their conventional parameter space (100 GeV ≲ M χ ≲ 100 TeV), a mass range accessible with current Imaging Atmospheric Cherenkov Telescopes. As ultraheavy dark matter (UHDM; M χ ≳ 100 TeV) has been suggested as an underexplored alternative to the WIMP paradigm, we search for an indirect dark matter annihilation signal in a higher mass range (up to 30 PeV) with the VERITAS γ -ray observatory. With 216 hr of observations of four dwarf spheroidal galaxies, we perform an unbinned likelihood analysis. We find no evidence of a γ -ray signal from UHDM annihilation above the background fluctuation for any individual dwarf galaxy nor for a joint-fit analysis, and consequently constrain the velocity-weighted annihilation cross section of UHDM for dark matter particle masses between 1 TeV and 30 PeV. We additionally set constraints on the allowed radius of a composite UHDM particle.