Experiments give shape to Higgs Boson

Physicists say they have learned more about the identity of the Higgs Boson, first theorised in the 1960s.

Physicists say they have learned more about the identity of the Higgs Boson, first theorised in the 1960s.

Physicists say they have learned more about the identity of the Higgs Boson, first theorised in the 1960s (Getty/AFP)

Physicists say they have learned more about the identity of the Higgs Boson, the elusive particle whose ground-breaking discovery was announced nearly two years ago.

Work at the Large Hadron Collider (LHC) - the particle smasher on the French-Swiss border where the breakthrough was made - has answered long-standing questions about how the Higgs behaves, they said on Sunday.

The Higgs was theorised in the 1960s as being the sub-atomic particle that gives other particles mass. Without it, matter would not exist.

Decades of work followed to explore the idea until on July 4, 2012, rival teams at the LHC announced they had independently found a particle consistent with the Higgs.

But further work was needed to flesh out this discovery and to see how it fits with the Standard Model, the conceptual framework for explaining visible matter in the Universe.

In a study published in the journal Nature Physics, one of the LHC teams said the boson behaves as predicted, and is not an "imposter that looks like it".

Analysis of the mountain of data from collisions at the LHC shows the boson decays neatly to a group of sub-particles called fermions, in line with Standard Model theory, the paper said.

"This is an enormous breakthrough," said Markus Klute of the Massachusetts Institute of Technology (MIT) who led the research at the LHC's Compact Muon Solenoid (CMS).

"Now we know that particles like electrons get their mass by coupling to the Higgs field, which is really exciting."

Finding the Higgs was only possible through the building of the LHC, the world's biggest laboratory, made up of a 27-kilometre ring-shaped tunnel.

An army of physicists from around the world sifted through the rubble left from billions of proton smashups, hunting for a telltale signature from a fleeting particle.

The initial discovery put the Higgs' mass at between 125 to 126 gigaelectronvolts, a standard unit of measurement at sub-atomic level.

Later analysis of the data from these experiments also found the boson has no "spin," and rapidly decays into pairs of photons (particles of light) and so-called W or Z bosons.

"We have now established the main characteristics of this new particle," said Klute in a press release issued by MIT.

"All of these things are consistent with the Standard Model."

Experiments at the LHC are currently on hold while the collider goes through an upgrade, although scientists are still trawling through reams of data generated from smashups before the shutdown.

Operations are due to resume in 2015, with a three-year program that will see scientists use more powerful collisions to explore theorised phenomena such as "super-symmetry" which may explain dark matter, the substance that makes up most of the Universe.


Share

3 min read

Published

Updated



Share this with family and friends


Get SBS News daily and direct to your Inbox

Sign up now for the latest news from Australia and around the world direct to your inbox.

By subscribing, you agree to SBS’s terms of service and privacy policy including receiving email updates from SBS.

Download our apps
SBS News
SBS Audio
SBS On Demand

Listen to our podcasts
An overview of the day's top stories from SBS News
Interviews and feature reports from SBS News
Your daily ten minute finance and business news wrap with SBS Finance Editor Ricardo Gonçalves.
A daily five minute news wrap for English learners and people with disability
Get the latest with our News podcasts on your favourite podcast apps.

Watch on SBS
SBS World News

SBS World News

Take a global view with Australia's most comprehensive world news service
Watch the latest news videos from Australia and across the world