Light Higgs Rumor

An internal paper at the ATLAS project set the world on fire on Friday when it showed signs at the four standard deviation of a possible Higgs-like particle with a mass of about 115 GeV, which is right where a lot of people think it ought to show up in the data. Previous studies have shown "bumps" of almost two standard deviations at the same mass but haven't been able to provide convincing proof that the data are more than a statistical fluke.

Skepticism abounds, however, because the magnitude of the effect in the diphoton channel observed is much larger than anyone had predicted. This could be a sign that something is wrong with the analysis in the as yet not peer reviewed paper, or could be evidence of not only a Higgs but also of at least a fourth generation of fundamental particles beyond the three known to exist (something that neutrino data has already hinted might be the case). For technical reasons, a prediction that there is at least a fourth generation of fundamental particle would still provide almost no information about its mass.

Alternately, there could be a 115 GeV mass particle that is not a Higgs. The properties that can be inferred from the data in this paper tend to favor a scalar particle, like a Higgs, but do not distinguish it from other possibilities.

For SUSY and string theory fans, a 115 GeV Higgs is great confirmation of what they expect, but a fourth or greater generation of fundamental particles could throw a serious wrench in their theories.