Evidence For 'New Physics' Means Universe Is Not As We Know It


First evidence that the universe is not as we know it has emerged from the Large Hadron Collider (LHC), the giant atom-smashing machine built to recreate conditions at the dawn of time.

Confirmation of the results, showing minute deviations in the behaviour of a sub-atomic particle, would indicate the existence of a 'new physics' model of the universe.

Our view and place in the universe may have to be revised

Until now scientists have relied on the 'Standard Model', a description of the nuts and bolts mechanics of the universe - its particles and forces - that has worked well but contains serious gaps.

For instance, the Standard Model cannot explain phenomena such as dark matter, invisible material that shrouds galaxies and holds them together, or gravity.

The term 'new physics' was coined to describe more fundamental theories that go beyond the Standard Model, some of which involve strange concepts such as tiny vibrating "strings" and extra dimensions.

A Spanish and French team has now announced results that could be the first indication of a New Physics reality.

They involve data from the LHCb, one of the giant detectors that form part of the LHC on the French-Swiss border.

Scientists were measuring the decay of a fundamental particle called the B meson. They revealed deviations from what was predicted by the Standard Model that show a coherent pattern, and are consistent with New Physics.

The findings amount to a significant 'proof' level of 4.5 sigmas - just under the level of five sigmas which is regarded as a bona fide discovery.

If confirmed by other teams, it amounts to a 'major event' pointing to a realm beyond the Standard Model, say the physicists.

Professor Joaquim Matias, from the Universitat Autonoma de Barcelona in Spain, who led the research, said: "We must be prudent, because more studies and more experimental measurements will be needed for confirmation. But if they are confirmed this is the first direct proof of New Physics, a more general theory than the current Standard Model."

Scientists are still excited about last year's discovery at the LHC of a type of Higgs boson, the particle thought to be responsible for mass that had been missing for five decades.

"If the Higgs completed the Standard Model puzzle, these findings could be the first piece in an even bigger puzzle," Prof Matias added.

One of the New Physics models that could explain the results proposes the existence of a new particle named Zprima, according to the scientists. But Prof Matias says this could be one of "lots of compatible models".

Large Hadron Collider

A second LHC team in charge of the CMS detector now wants to repeat the measurements to see if it can corroborate the results. New data is also being added by the LHCb team to improve the statistics.

Two of the LHC's central goals were finding the Higgs boson and uncovering evidence for New Physics.

The LHCb detector is designed to study rare decays involving quarks, the most basic building blocks of matter.

A B meson is formed by a b quark and a d antiquark. On July 19 at the European Physics Society's annual meeting in Stockholm, Prof Matias presented his team's theoretical predictions of how a B meson should decay into other elementary particles.

The researchers forecast how the decay should alter in a New Physics scenario. The experimental results from the LHC appear to support their predictions.

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