CERN scientists reveal most precise measurement of Higgs boson mass

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Physicists at the European Organisation for Nuclear Research (CERN) have for the first time revealed the most accurate measurement of mass of the Higgs boson yet by combining the work at ATLAS and CMS experiments. The combined results on the mass of the Higgs boson were unveiled at a conference Tuesday in La Thuile, western Italy.

Using different technologies, the labs Atlas and CMS found the elusive particle had a mass of 125.09 gigaelectronvolts (GeV), with a margin of error of 0.24 GeV either side.

The figure “corresponds to a measurement precision of better than 0.2 percent,” CERN said in a press release. “It is the most precise measurement of the Higgs boson mass yet and among the most precise measurements performed at the LHC to date.”

The Higgs boson is an essential ingredient of the Standard Model of particle physics – the theory that describes all known elementary particles and their interactions. The particle, which is believed to confer mass, was theorised in 1964, but confirming its existence took 48 years.

The confirmation of existence through experiments run by the particle collider earned Peter Higgs and Francois Englert the 2013 Nobel Prize in physics.

Compact Muon Solenoid (CMS) lab spokesperson Tiziano Camporesi said: “The Higgs Boson was discovered at the LHC in 2012 and the study of its properties has just begun. By sharing efforts between Atlas and CMS, we are going to understand this fascinating particle in more detail and study its behaviour.”

The LHC is gearing for a restart, by the end of May or early June, after a two-year upgrade.

“While we are just getting ready to restart the LHC, it is admirable to notice the precision already achieved by the two experiments and the compatibility of their results,” says CERN Director of Research Sergio Bertolucci. “This is very promising for LHC Run 2.”

The facility comprises a 27-kilometre (17-mile) ring-shaped tunnel, in which two beams of protons are sent in opposite directions.

Powerful magnets bend the beams so that they collide at points around the track where four laboratories have clusters of sensors.

Some of the protons smash together, creating sub-atomic rubble that may hold clues to novel particles, while other particles survive the collision and continue around the ring.

To achieve this result, Atlas and CMS bring together more than 5,000 scientists from over 50 countries.