A very heavy sneutrino as viable thermal dark matter candidate in U(1)′ extensions of the MSSM

Manuel Drees, Felipe A. Gomes Ferreira
2019 Journal of High Energy Physics  
We study the Standard Model singlet ("right-handed") sneutrino $\tilde \nu_R$ dark matter in a class of $U(1)'$ extensions of the MSSM that originate from the breaking of the $E_6$ gauge group. These models, which are referred to as UMSSM, contain three right--handed neutrino superfields plus an extra gauge boson $Z'$ and an additional SM singlet Higgs with mass $\simeq M_{Z'}$, together with their superpartners. In the UMSSM the right sneutrino is charged under the extra $U(1)'$ gauge
more » ... 1)'$ gauge symmetry; it can therefore annihilate via gauge interactions. In particular, for $M_{\tilde \nu_R} \simeq M_{Z'}/2$ the sneutrinos can annihilate by the exchange of (nearly) on--shell gauge or Higgs bosons. We focus on this region of parameter space. For some charge assignment we find viable thermal $\tilde \nu_R$ dark matter for mass up to $\sim 43$ TeV. This is the highest mass of a good thermal dark matter candidate in standard cosmology that has so far been found in an explicit model. Our result can also be applied to other models of spin$-0$ dark matter candidates annihilating through the resonant exchange of a scalar particle. These models cannot be tested at the LHC, nor in present or near--future direct detection experiments, but could lead to visible indirect detection signals in future Cherenkov telescopes.
doi:10.1007/jhep04(2019)167 fatcat:bpurkt3rxfecfe63eaa64o4xhu