Theory of matter may need rethink

[DesertFox]

<font size=1>25 Mar 04</font>

Particle physicists have seen a rare happening that may force a rethink of current theories of sub-atomic matter.

After watching more than seven trillion disintegrations of the kaon particle they have seen three peculiar events when they expected to see just one. ...

The experiment looked at the disintegration of a sub-atomic particle called the K-meson or kaon.

It can decay in a number of ways. One involves it turning into a charged pion particle, a neutrino, and an anti-neutrino.

Physicists regard this decay pattern as especially interesting because it may reveal new effects not accounted for in the so-called Standard Model.

So far they have constructed a theory around 16 particles that make up all matter called the Standard Model of fundamental particles and interactions.

The Standard Model predicts that this particular event should occur only once in every 13 billion decays.

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More (http://news.bbc.co.uk/2/hi/science/nature/3564273.stm)

[DesertFox]

<font size=1>6 Dec 01</font>

The most sought after object in particle physics, the Higgs boson, may not even exist.

It's more likely than not that there is no Higgs

This is the astonishing conclusion of researchers at the Cern nuclear physics lab near Geneva who have just reviewed five years' worth of data from experiments they thought would confirm the legendary particle's role in the construction of the Universe.

The Higgs, according to the Standard Model of particle physics, is the particle that explains why all others have mass. Its importance is so central to current thinking that some have even dubbed it the "God particle".

But the Cern researchers have told New Scientist magazine that studies in its giant accelerator which should have shown up the presence of the Higgs found absolutely nothing - and this could mean particle physics having to revisit some of its most cherished ideas.

If there is no Higgs, science will be left totally unable to explain mass.

More (http://news.bbc.co.uk/2/hi/science/nature/1695390.stm)

[DesertFox]

<font size=1>10 Mar 04</font>

A scientist says one of the most sought after particles in physics - the Higgs boson - may have been found, but the evidence is still relatively weak. ...

... there is a 9% probability that the signal could be background "noise". ...

The Higgs boson is thought to be highly unstable and, once produced, should quickly decay. ...

Physicists have observed 16 particles that make up all matter under the Standard Model of fundamental particles and interactions.

But the sums do not quite add up for the Standard Model to be true if these particles are considered alone. If only 16 particles existed, they would have no mass - contradicting what we know to be true in nature.

Another particle has to give them this mass. Enter the Higgs boson, first proposed by University of Edinburgh physicist Peter Higgs and colleagues in the late 1960s.

Their theory was that all particles acquire their mass through interactions with an all-pervading field, called the Higgs field, which is carried by the Higgs boson.

The Higgs' importance to the Standard Model has led some to dub it the "God particle". ...

More (http://news.bbc.co.uk/2/hi/science/nature/3546973.stm)

[DesertFox]

<font size=1>11 June 03</font>

A huge cavern - large enough to house a cathedral - has been dug out beneath the Franco-Swiss border to hold the largest single scientific instrument ever built.

The Atlas detection equipment will be five stories tall and weigh 7,000 tonnes. Its task is to search for a crucial sub-atomic particle called the Higgs boson ...

Atlas, along with three other particle detectors, will form the basis of the large hadron collider (LHC) due to begin operation in April 2005.

The LHC is a circular, underground tunnel 27 kilometres (16.8 miles) long in which two beams of protons travelling in opposite directions will smash into each other; scientists will investigate the debris from the collision.

...Building the cavern for the Atlas detector has been a difficult task. Engineers had to freeze an underground river using liquid nitrogen to create a permafrost through which they could excavate. ...

Scientists estimate that when the LHC is in operation, it will produce an enormous quantity of data: every second it will yield an equivalent to all the information handled by the world's telecom companies during an entire year.

Searching for the Higgs boson will be far, far more difficult than looking for the proverbial needle in a haystack.

If the Higgs particle exists, scientists should detect it in just one in every 10 [trillion] collisions. With an estimated 800 million collisions every second when the LHC is up to speed, there should be one Higgs particle produced every day.

Entire article (http://news.bbc.co.uk/2/hi/science/nature/2978892.stm)