High-scale validity of a model with Three-Higgs-doublets

We consider a three-Higgs doublet scenario in this paper, invariant under the discrete group S3 , and probe its high-scale validity by allowing the model parameters to evolve under a renormalization group. We choose two particular alignments of vacuum expectation values (vev) for our study, out of a set of several such possible ones. All three doublets receive nonzero vacuum expectation values in the first case, and in the second case, two of the doublets remain without vev. The constraints on the parameter space at low energy, including the measured value of the Higgs mass and the signal strengths, oblique corrections and also measurements of relic density and direct detection rates are juxtaposed with the conditions of vacuum stability, perturbativity and unitarity at various scales. We find that the scenario with three nonzero vevs is not valid beyond 107 GeV, assuming no additional physics participates at the intermediate scales. On the contrary, the scenario with only one nonzero vev turns out to be a successful model for cold dark matter phenomenology, which also turns out to be valid up to the Planck scale at the same time. Stringent restrictions are obtained on the model parameter space in each case. Thus, the S3 symmetric scalar sector emerges as an ultraviolet complete theory.