Sunday, September 4, 2011

The case of the missing Higgs

As physicists, and those who follow physics, know, the Higgs boson is the most sought after particle in physics. The fanciful have even called it "the God particle". They also know that it is proving to be even more elusive than the snark.

The hunters had turned hopeful last month, when data from the Large Hadron Collider at CERN showed a flurry of events that were consistent with the Higgs. Two independent detectors, the ATLAS and the CMS (Compact Muon Solenoid) saw an excess of W bosons, an event considered to be a precursor of the Higgs, in the neighbourhood of 144 GeV. It was hoped that the signal would strengthen, and that the Lepton Photon meeting held in Mumbai in August would announce the discovery of the Higgs. Unfortunately, the latest results which use about twice the data show that the confidence levels in the data have fallen from 2.8 sigma to 2 sigma, i.e. from 99 percent to 95 percent, as researchers have included the effects of other processes that could give an excess of W bosons. (Followers of this blog will remember that 5 sigma results are required before a particle is declared as being discovered). What has been stated with confidence are the energy ranges where the Higgs is not, viz. between 145 and 400 GeV, and patches between 146 and 466 GeV. The Higgs might actually lurk at the lower ends of the energy spectrum viz. between 120 and 140 GeV. More data is awaited, and maybe a result by 2012.

Tailpiece: Why is the Higgs so eagerly awaited? The following hoary chestnut tells it all (thanks, Ashutosh): A Higgs boson walks into a church. The priest says, "We don't allow Higgs bosons in here." The Higgs boson says huffily, "But without me how can you have mass?"

This blog post is by Neelima Gupte and Sumathi Rao.


Meena said...

Despite being in an institute with a majority of physicists, I hadn't heard that chestnut. Loved it!

Neelima said...

You need Rahul for these things! He would have produced ten more.

Meanwhile, here's one more.
A Higgs-Boson walks into a bar. The bartender says "You know, there were some guys looking for you."

AmOK said...

For physicists, which is more fundamental- mass or wait? We will need Rahul to rule on that one!

Rahul Basu said...

Mass! Thanks for the addition.