Back when physicists were feverishly hunting for the top quark -- the Higgs boson search of the 1990s -- I interviewed a scientist who compared the search not to trying to find one needle in a haystack, as the proverbial saying goes, but to trying to find one needle in an entire field of haystacks.
Eventually, the D-Zero and CDF collaborations at Fermilab succeeded in nailing down the top quark, and jubilation ensued. But the Higgs is proving even more elusive than the top quark -- akin, perhaps, to searching for a needle in a Chicago-sized city filled with haystacks.
ANALYSIS: The Higgs Boson May Have 'Five Faces'
So it was welcome news yesterday when an international collaboration of scientists working at Fermilab's D-Zero and CDF detectors announced -- at the International Conference on High Energy Physics in Paris -- their latest results, which cut down significantly on the number of "haystacks" in which the Higgs "needle" might be hiding.
Essentially what they've done is narrow the range of what the Higgs' mass is likely to be. This, in turn, helps them focus their future searches by excluding the most unlikely possible masses.
For those who don't know how this process works, it is a daunting, data-intensive quest. You have to know where to look if you're going to conduct an effective search. At both the Tevatron and the Large Hadron Collider, there are billions of particle collisions that occur with every run, and there's just no way the detectors and computers can record and store such a huge amount of data.
SLIDE SHOW: Top 5 Misconceptions About the Large Hadron Collider.
So particle physicists use many different types of detectors in combination, each with a specific function. The detectors act as a filter, picking out just those signals that indicate a likely event for the particle of interest, out of the tens of thousands of signals created every millionth of a second inside the accelerator.
In the case of the Higgs, they've programmed the detectors to seek out specific "trigger events" within carefully delineated energy ranges -- this is what the theorists bring to the table -- and sift through those results in their data analysis.
It's still a huge number of events. The latest D-Zero and CDF results derive from 500,000 billion -- yes, that's a lot of zeros! -- proton-antiproton collisions dating back to 2001.
Each team crunched their own numbers to arrive at a result, then they combined their respective analyses to get the new findings. And they've ruled about pretty much a quarter of the ranges of mass previously thought possible for the Higgs.
ANALYSIS: Higgs Boson Discovered? Not So Fast.
So now, instead of 100 haystacks, they only have to search through 75. So now it's more like searching for a needle in a slightly smaller city filled with haystacks.
Hey, every little bit helps, and this really is a significant step forward and we can expect a further narrowing of the range of interest in the near future, as D-Zero spokesman Sten Soeldner-Rembold (University of Manchester) was happy to point out for the official press release:
"Our latest result is based on about twice as much data as a year and a half ago. As we continue to collect and analyze data, the experiments will either exclude the Standard Model Higgs boson in the entire allowed mass range, or we'll go on to see first hints of its existence. There is less and less room for the Higgs boson to hide now."
And don't forget that the LHC is hot on the Higgs trail, too. The same conference also featured results from its first three months of operation, with data gathered at the highest energies yet achieved in a particle accelerator.
We'll be plowing through all those remaining haystacks in no time, uncovering all the potential hiding places until we find that tricky little particle at last.
Image: Simulation of a detection of the Higgs boson in the CMS equipment at the LHC (CERN)
Tags: Laboratories, Large Hadron Collider, Particle Physics, Particles
comments ( )