/ 4 July 2012

Like a boson: Higgs-like ‘God particle’ discovered

A representation of traces of traces of a proton-proton collision measured in the Compact Muon Solenoid experience in the search for the Higgs boson.
A representation of traces of traces of a proton-proton collision measured in the Compact Muon Solenoid experience in the search for the Higgs boson.

The particle is "consistent with [the] long-sought Higgs boson," Cern said, adding that further data was needed to identify the find.

Scientists have wrestled with the elusive particle for nearly half a century.

"We have reached a milestone in our understanding of nature," said Cern director general Rolf Heuer.

"The discovery of a particle consistent with the Higgs boson opens the way to more detailed studies, requiring larger statistics, which will pin down the new particle's properties, and is likely to shed light on other mysteries of our universe."

Finding the Higgs would validate the Standard Model, a theory which identifies the building blocks for matter and the particles that convey fundamental forces.

It is a hugely successful theory but has several gaps, the biggest of which is why some particles have mass and others do not.

Mooted by British physicist Peter Higgs in 1964, the boson is believed to exist in a treacly, invisible, ubiquitous field created by the Big Bang some 13.7-billion years ago.

When some particles encounter the Higgs, they slow down and acquire mass, according to theory. Others, such as particles of light, encounter no obstacle.

A little more on the Higgs boson

What is it?
The Higgs boson is conceived as a sub-atomic particle that confers substance.

It is conceived as existing in a treacly, invisible field that was created after the "Big Bang" and pervades the Universe. Higgs bosons "stick" to fundamental particles of matter, dragging on them and then decay themselves into another form.

Some of these particles interact more with the Higgs than others and thus have greater mass, according to the theory. But particles of light, also called photons, are impervious to it and have no mass.

Why is it important?
The origin of mass – meaning the resistance of an object to being moved – has been fiercely debated for decades.

Finding the Higgs boson would vindicate the so-called Standard Model of physics, a theory that developed in the early 1970s, which says the Universe is made from 12 particles which provide the building blocks for all matter.

These fundamental particles are divided into a bestiary comprising six leptons and six quarks, which have exotic names such as "strange," "up", "tau" and "charm".

Why is it called the Higgs boson?
The name comes from a British physicist, Peter Higgs (83) who conceived of a field of mass-conferring particles in 1964 and became the first to publish his idea.

Important theoretical work was also done separately by Belgian physicists Robert Brout, who died in 2011, and Francois Englert (79).

Bosons are non-matter particles which are force carriers, or messengers that act between matter particles.

The interaction gives rise to three fundamental forces – the strong force, the weak force and the electromagnetic force. There is a fourth force, gravity, which is suspected to be caused by a still-to-be found boson named the graviton.

How has the Higgs been hunted?
The quest for the Higgs has been carried out at colliders: giant machines that smash particles together and sift through the sub-atomic debris that tumbles out.

The big daddy of these is the Large Hadron Collider (LHC), operated by the European Organisation for Nuclear Research (CERN) in a ring-shaped tunnel deep underground near Geneva.

Smash-ups generated at the LHC briefly generate temperatures 100 000 times hotter than the sun, replicating the conditions that occurred just after the universe's creation in the "Big Bang" nearly 14-billion years ago.

But these concentrations of energy, while violent, occur only at a tiny scale.

On Wednesday, CERN scientists said they had found a new particle that was "consistent" with the Higgs, but further work was needed to determine what it was.

Why the 'God particle'?
The Higgs has become known as the "God particle", the quip being that, like God, it is extremely powerful, exists everywhere but is hard to find.

In fact, the origin of the name is rather less poetic.

It comes from the title of a book by Nobel physicist Leon Lederman whose draft title was The Goddamn Particle to describe the frustrations of trying to nail the Higgs.

The title was cut back to The God Particle by his publisher, apparently fearful that "Goddamn" could be offensive. – AFP