Why is the Higgs Messon Important?

Answer 1

I presume you mean the Higgs Boson.

If it exists in the way as it is predicted to exist, then our over-all paradigm of particle physics -- called the "Standard Model", simply because it has proven itself to be SO good -- would continue to be the model that is followed for now. If the Higgs does NOT exist, then this model -- which has been proven correct in over forty years of experiment -- would have to be jettisoned or heavily modified. Either result would be a major achievement for particle physicists.