While the flurry of theoretical speculations on the 750 GeV bump spotted by ATLAS and CMS in their 13-TeV diphoton data continues (over 300 papers written to interpret it, in little more than 3 months), the question on whether it is a fluctuation or something else remains on the table, and keeps all of us wondering.
What if it is real ?
I mean – come on. We all like to dream, but a totally unexpected signal appearing out of the blue like that is beyond what even the wildest dreamer among my colleagues would have hoped for. And yet it makes sense to ask the question, for its formidable implications.
As far as high-energy particle physics in general is concerned, a new resonance at 750 GeV would completely revolutionize the whole field. We’d get more funding for fancier accelerators, we’d attract hords of students eager to study and conquer the new world (for indeed, a 750 GeV boson does not come alone!!). Particle physics with accelerators would triumph and a new era like the fifties of last century would start.
As the coordinator of a ITN network that wrote on stone what the four dozen particle physicists who participate to it will be doing in the next 3.5 years, I need to also consider what the new boson would change. The European Community is not happy to see a change in the program of a funded project. But I know nobody in ATLAS or CMS who would not like to jump in and start studying the new world opening before our eyes. Would our ITN stay stuck to its original plan ?
Well, it turns out that we wrote a very resilient programme, not just a successful one (in terms of chances to be funded and in terms of the score it was given by the EU evaluators). I went back to read the details of the four scientific work packages that summarize the research program of our network, and I found nothing that would prevent AMVA4NewPhysics to focus on the physics of the 750 GeV boson.
First of all, it has to be noted that the new particle, if it is one, is a Higgs-like particle. So all what we wrote about studying in more detail Higgs physics would stand. The deliverables we promised to deliver, and the milestones we set to ourselves, are easy to be built around the study of a new Higgs boson. But also the things we promised in terms of model-independent and global searches of new physics would of course stand – and all the more so, given that now we would have a decent chance of really finding new stuff!
So, I must say I am not worried. A new 750 GeV boson would be a very, very good problem to have. And it would be solvable. If only. It were. True.
But it is not. Worry not, the fairy particle will vanish in the time it takes to fill a semi-log histogram, as it has appeared. It is too good to be true, so it must be false, alas. But particle physics will not die if we do not find new physics at the LHC: there is a whole lot we still do not understand, particularly in the spectrum of hadronic resonances, in the details of QCD bound states, in the puzzles of CP violation, in the neutrino puzzles. Just a tad less exciting than a forest of new mushrooms to pick up as we go along.