Saturday, February 18, 2012

Tevatron: CDF may reveal 3-sigma 125 GeV Higgs bump

Or its absence

See an update: CDF sees nothing in the diphoton channel

Almost half a year after its demise, the Tevatron still seems to be intellectually alive. The CDF Collaboration plans to publish several papers.

One of them is a new high precision measurement of the W-boson and top-quark masses. Another one might be a 3-sigma evidence supporting a Higgs boson near 125 GeV, as seen by the LHC:
AAAS press release, Cosmic Log at MSNBC, SciAm blogs, Discovery News, Macleans, Vancouver Sun blogs
3 sigma is the predicted strength of the signal of the Standard Model Higgs whose mass is 125 GeV, as applied to the recorded CDF collisions.

Needless to say, the combined evidence from CDF, CMS, and ATLAS would be enough for a 5-sigma "discovery". Nevertheless, your humble correspondent has developed some instinctive skepticism when it comes to the CDF claims so I would better not do such combinations too officially...

The Higgs bump announcement should come soon, according to Rob Roser, the CDF's boss. My understanding of the AAAS press release is that it should be today, on Saturday, during the last day of an AAAS meeting (7:00-8:30 pm Pilsen Winter Time) or by February 20th when the Vancouver AAAS meeting ends. On February 23rd which is still very soon, they should release their new top/W precision measurements. Roser says that the knowledge of the W and top masses allows one to calculate the Higgs mass. That shows that he is confined in the Standard Model. That's what makes it less likely that the CDF will report on some non-SM features of the Higgs – even though it could be pretty capable to observe the elevated diphoton branching ratio...

Alternatively, the CDF may claim that 125 GeV is excluded etc. Last year, they used a very large set of collisions around 8/fb at 2 TeV and the excess near 125 GeV was less than one sigma. However, if this is what CDF tells us, I personally won't believe them, after some other bizarre statements they have made in the last year.

Stay tuned.

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