Monojets from compressed weak frustrated dark matter

We extend the so-called hyperchargeless Higgs triplet model to include a weak triplet of Dirac fermions and a Dirac fermion <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:mi>X</a:mi></a:mrow></a:math> transforming trivially under the Standard Model gauge group. We are motivated in part by a collection of anomalies that can be interpreted as a new scalar state with a mass of approximately 152 GeV coupling to <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mi>W</c:mi></c:math> but not <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:mi>Z</e:mi></e:math> bosons, which may be consistent with the electrically neutral triplet scalar in this model (provided that it mixes very slightly with the Standard Model Higgs boson). Meanwhile, the lightest neutral fermion in the model is stable and can be thermal dark matter with the correct relic abundance if it mixes lightly with the neutral triplet fermion, such that the dark matter is composed mostly of <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"><g:mi>X</g:mi></g:math>. Because <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" display="inline"><i:mi>X</i:mi></i:math> couples to the Standard Model only through a Yukawa-like interaction with the pair of triplets, this model falls into the frustrated dark matter paradigm. Finally, the spectrum of exotic fermions in this model can exhibit the strong compression favored by the current excess in the monojet channel, and it evades multijet constraints in the region favored by monojets. In this work, we explore this model’s phenomenology and compare the parameter space regions best suited to each of the aforementioned excesses and constraints.