Sunday, August 17, 2003

செய்திகளின் முக்கியத்துவம் கருதி இங்கும் நேரடியாகக் கீழே தரப்பட்ட செய்தியும் ஆங்கிலத்தில் தரப்பட்டுள்ளது....

இவ்விரண்டு செய்திகளும் New Scientist.com இற்குச் சொந்தமானவை.


Particle physicists play hunt the particle

10:15 16 August 03
Jenny Hogan

A competition is running to test the detective skills of the physicists who will grapple with data from the next generation of particle accelerators. They have been given two months to find secret physics hidden in a simulated data set.

The data is intended to mimic the results that will pour out from the Large Hadron Collider (LHC) when it is switched on in 2007. The LHC, under construction in tunnels beneath the French-Swiss border at CERN, will be the most powerful particle accelerator in the world.

Beams of protons will be fired in opposite directions down the tunnels and when two collide, their energy will be ejected in a spray of new particles. Studying the debris from such collisions has helped physicists to piece together the rules of the subatomic world.

But "the LHC opens up a new energy regime, so you are never sure what you might find" says Ian Hinchliffe, from Lawrence Berkeley National Laboratory in California, and one of the competition's organisers.

Blessed or cursed

Physicists will use software to analyse the LHC data. But the danger is that the programs will spot only the ordinary events predicted by the "Standard Model" of particle physics, not the unexpected events that can lead to new discoveries.

"We are presently blessed - or perhaps cursed - with an amazingly accurate Standard Model," says Bruce Knuteson, who helped to discover a new sub-atomic particle at the Fermilab particle accelerator, in Illinois. Many refinements and extensions to the Standard Model have been suggested, he says, but there is as yet "no compelling evidence for any of them".

The LHC could create miniature black holes, shed light on new dimensions, reveal a super-symmetric family of particles that mirrors those already found, or perhaps produce Higgs bosons - particles that would explain why the Universe has mass.

Physicists need to find the signatures of these events in the data. Although they can test their programs using their own mock results, knowing what to look for biases the trial. This competition aims to recreate the unknowns in a real experiment, so Hinchliffe will not reveal which exotic physics he has buried in the data.

Secret prize

The competition's organisers simulated six million events. This took 300 hours of computer time, but corresponds to just a few days of results from the collider. Of these, 600,000 were selected and made available to the competitors.

Chris Lester, a particle physicist at the University of Cambridge, UK, started work as soon as the data was released. "We reckon we have found at least two new particles in there" he says.

The competition is open to the 2000 physicists around the world who are part of ATLAS, a project that will run on the LHC. Participating teams have until 7 September to submit a report, which will be judged on accuracy and thoroughness. There will be a prize, says Hinchliffe, but "it won't be anything expensive".

If the challenge helps to improve the programs, a larger competition will be run in 2004.

10:15 16 August 03

பதிந்தது <-குருவிகள்-> at 7:35 pm

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