[ The first two entries of this live blogging series are available here (part 1) and here (part 2) ]
7 AM. In thirty minutes the doors of the Main auditorium will open, and people will flood in. I have no idea whether it will be a tidy flow or a wild rush, but I suspect that the latter is more probable, given the strong feelings involved (people losing a night of sleep; the historical importance of the event; the young age and varied nationality of the people queueing up; the absence of suitable infrastructure to guide the queue).
7.20AM Will it be a model-independent discovery or a model-dependent one ? Answering this question is not easy at all. First of all, when we search for a particle in a certain final state we are already making assumptions on the way it is produced. For instance, looking at two-photon final states one might say "oh, I am just making a model-independent search of a narrow resonance decaying to two photons", but then why should one include in one of the subcategories events which feature two very high-energy, very-forward hadronic jets -those that provide the "forward tag" of a vector-boson-fusion production mode ?
The model dependence is everywhere. It is built in the test statistics which we use to quantify the confidence level, the p-values, everything. If the particle had a different spin than zero, there would be a significant difference in the discrimination power of our selection tools.
So, claiming a discovery is a must - we have very large significances in two experiments that see basically the same thing. But claiming a discovery of the standard model Higgs boson requires to attach some disclaimers at the end. Surely, we have looked for the standard model Higgs boson and we have found something which looks like the real thing. But it could be a SUSY Higgs, or even something different, like a graviton. It could. We certainly will never be sure, in some sense. I think the fair thing to do is to say we discovered a particle whose properties agree with those expected from a Higgs, and that more studies will clarify beyond reasonable doubt the exact nature of the particle.
Higgs Live Blogging 3 - Fundamental Bits To Decrypt The Seminars