Two component singlet-triplet scalar dark matter and electroweak vacuum stability

We propose a two component dark matter setup by extending the Standard Model with a singlet and a hyperchargeless triplet scalars, each of them being odd under different Z₂ symmetries. We observe that the interconversion between the two dark matter components allow a viable parameter space where masses of both the dark matter candidates can be below TeV, even though their individual contribution to single component dark matter rules out any such sub-TeV dark matter. We find that a lighter mass of the neutral component of the scalar triplet, playing the role of one dark matter component, compared to the singlet one is favored. In addition, the setup is shown to make the electroweak vacuum absolutely stable till the Planck scale, thanks to Higgs portal coupling with the scalar dark matter components.