Indirect Detection for Higgs Portal Majorana Fermionic Dark Matter.

We study the |$\gamma$| -ray signal emitted from dark matter (DM) pair annihilation in the Higgs portal Majorana fermion DM model. In the model, a Majorana fermion DM |$\chi$| couples with the Standard Model (SM) Higgs field |$H$| through a higher-dimensional term |$-{\cal L}\supset H^\dagger H \bar{\chi }\chi /\Lambda$|⁠ , where |$\Lambda$| is a cutoff scale [ 1 ]. The pair annihilation of |$\chi$| through the above term produces the Higgs boson and the longitudinal modes of |$W,Z$| gauge bosons. The Milky Way dwarf spheroidal satellite galaxies (dSphs) are used as the most promising targets to search for the |$\gamma$| -ray signal of the model, due to high DM density and lack of astrophysical backgrounds. The Fermi Large Area Telescope (Fermi -LAT) is used for the search, for its high sensitivity [ 2 ]. In this work, we use 14-year Fermi -LAT data from 16 dSphs, to constrain the DM pair annihilation cross section for the DM mass range from 125 GeV to 100 TeV. [ABSTRACT FROM AUTHOR]