Higgs boson and the stability of the Universe - ICHEP 2014

Graph BBC News - Science and Environment

BBC science editor Paul Rincon writes about the preparations currently going on in order to restart the Large Hadron Collider in Cern next year. He outlines one of the numerous questions that the about 10 billion euro instrument might provide answers to: how stable is the Universe? Will it exist to infinity or will it be destroyed some day?

The answer is depends on the measured mass of Higgs boson - the cause of gravity according to the Standard Model. The matter is discussed in the 37th International Conference on High Energy Physics (ICHEP) held on July 2-9 2014 in Valencia, Spain.

At ICHEP, other scientists are expected to outline details of a refined mass for the fundamental particle, which has been measured at approximately 125 gigaelectronvolts (GeV). For those outside the particle physics community, this might seem like a minor detail. But the mass of the Higgs is more than a mere number.

There's something very curious about its value that could have profound implications for the Universe. Mathematical models allow for the possibility that our cosmos is long-lived yet not entirely stable, and may - at some indeterminate point - be destroyed.

"The overall stability of the Universe depends on the Higgs mass - which is a bit funny," said Prof Jordan Nash, a particle physicist from Imperial College London, who works on the CMS experiment at Cern.

"There's a long theoretical argument which I won't go into, but that value is intriguing in that it sits on the edge between what we think is the long-term stability of the Universe and a Universe that has a finite lifetime."

To use an analogy, imagine the Higgs boson is an object resting at the bottom of a curved slope. If that resting place really is the lowest point on the slope, then the vacuum of space is completely stable - in other words, the Higgs is in the lowest energy state and can go no further.

However, if at some point further along this slope, there's another dip, the potential exists for the Universe to "topple" into this lower energy state, or minimum. If that happens, the vacuum of space collapses, dooming the cosmos.

READ THE ENTIRE ARTICLE IN BBC News - Science and Environment July 1, 2014