Last week scientists working on the Large Hadron Collider in Geneva updated their colleagues on the newly-discovered Higgs boson. They revealed what they now know about the particle – and so far, it is behaving exactly as they expected. While this might seem like good news, for some people it is the opposite, because a well-behaved Higgs might rule out some intriguing new physics theories.
The Higgs – the particle which explains why others have mass – is incredibly unstable and only exists for a fraction of a second before decaying into other, more common particles. Any information about it comes second-hand from these other particles, and working out the properties is rather like putting together clues in a Sherlock Holmes tale, only with more mathematics.
Finding the Higgs in July was a wonderful coup for the LHC, but there now follows years of painstaking work to determine its precise properties. If the Higgs behaves even a smidgen differently from predictions, then it might point scientists in the direction of a new theory.
One particularly popular idea has the rather grand name of “supersymmetry”, which as we wrote on this blog last week, is looking less likely to be true.
There are lots of problems with current theories about the Universe – they don’t explain dark matter, and particle physics is completely incompatible with Einstein’s theories of gravity. Supersymmetry solves some of these issues in a whizz of complicated mathematics, but requires the existence of a whole family of new particles. If they exist, the Higgs’ properties should reveal them.
The results announced on Wednseday in Japan don’t lend the under-fire supersymmetry any more support. They suggest that so far, the Higgs behaves just as our current theory predicts it should. Specifically, when it decays, it turns into different types of particles at the rates we expect.
To some in the community, the Higgs’ conformity is rather disappointing. But not all of the analysis was ready for the Japan conference and there is still uncertainty around the results that were announced, and supersymmetry still could work.
Even though the LHC has already analysed more data in two years than its predecessor managed in twenty, the measurements are not yet particularly precise, and the Higgs may still harbour surprises. The LHC still has not detected a Higgs decaying into quarks (the smallest unit of matter), for example – we just know that since we haven’t seen it yet, it can’t happen often. In other words: watch this space.
Visitors to the Science Museum will have a chance to get up close and personal with the LHC at a new exhibition opening in November 2013.