CERN have happily announced the arrival of a new Boson but so far are being a bit cagey about what to call it. Is it the Higgs? Their caution as experimenters is perfectly laudable. They should show that they are keeping an open mind, but theorists are independent of the process of discovery and do not need to be so reticent.
The facts are that the boson discovered with a mass of about 125 GeV or 126 GeV interacts with a wide range of particles in exactly the way the Higgs boson should. Its decay modes to Z, W, b and tau have just the right ratios and its production has also been tested in different ways confirming indirectly that its coupling to the top quark is also about right. Its spin could be 0 or 2 but 0 is much more likely. All these features point to the standard model Higgs boson.
The only fly in the ointment is its decay rate to two photons. This is nearly twice as large as expected. The significance of the discrepancy with the standard model is about 2.5 sigma. It could be a fluke. We have learnt to show some healthy skepticism when it comes to observations of physics beyond the standard model. However it is also consistent with an enhancement due to the presence of another charged boson. If that boson exists it must have a mass at least a bit larger than the W otherwise the Higgs would decay to this particle in pairs and we would see the effect on the other decay rates. It can’t be too massive otherwise it would not enhance the diphoton rate enough. But it is likely to be possible to find a range of masses and properties that is consistent with all the observations.
So it is not necessary to invoke any properties for the observed boson that are any different from the standard model. Separate new physics will suffice. So the observed boson passes several tests required by the Higgs and I think that it is reasonable to assume that is indeed the Higgs boson until some observation suggests otherwise. It will always be possible to think of other models that could fit the facts, but they are not likely to be quite as economical as the standard model. It would be a disservice to the theorists who provided the theory 50 years ago if we continue to refuse to acknowledge the clear nature of this discovery when there is no evidence to the contrary. They predicted it would be just like this and It is the Higgs boson. Congratulations to all the experimenters and theorists who made this dream come to life.
Update: Here is the global Higgs combination. Is that conclusive enough now?