Little Higgs dark matter after PandaX-II/LUX-2016 and LHC Run-1

Abstract

In the Littlest Higgs model with T-parity (LHT), the T-odd heavy photon (AH) is weakly interacting and can play the role of dark matter. We investigate the lower limit on the mass of AH dark matter under the constraints from Higgs data, EWPOs, Rb, Planck 2015 dark matter relic abundance, PandaX-II/LUX 2016 direct detections and LHC-8 TeV monojet results. We find that (1) Higgs data, EWPOs and Rb can exclude the mass of AH up to 99 GeV. To produce the correct dark matter relic abundance, AH has to co-annihilate with T-odd quarks (qH) or leptons (ℓH); (2) the LUX (PandaX-II) 2016 data can further exclude mAH< 380(270) GeV for ℓH-AH co-annihilation and mAH< 350(240) GeV for qH − AH co-annihilation; (3) LHC-8 TeV monojet result can give a strong lower limit, mAH> 540 GeV, for qH-AH co-annihilation; (4) future XENON1T(2017) experiment can fully cover the parameter space of ℓH-AH co-annihilation and will push the lower limit of mAH up to about 640 GeV for qH-AH co-annihilation. © 2016, The Author(s)