CERN says it only has one more variable to confirm before it can officially confirm that the particle it discovered is indeed the hypothetical Higgs boson.
The particle is currently officially labeled as Higgs-like, referring to its similarities to an imaginary particle described by physicist Peter Higgs among others. His model (in very simplified terms) describes particles traveling through a sticky energy field that slows down the particles and gives them mass. This in turn would form the basis of much of our understanding of how things work in the universe, for example the way objects are affected by gravity.
If the model is correct, there must be a specific particle that hasn’t previously been detected, known as the Higgs boson. CERN announced the discovery of a new particle last July and is still working on identifying it.
With Sherlock Holmes-style logic, this process has largely involved trying to eliminate every other possibility for what CERN found until the only possible explanation is that it is indeed the Higgs boson. Much of this research has involved testing the way the particle interacts with other particles.
CERN now says the last remaining factor is confirming the particle’s spin. This is a characteristic of each particle, though the name is more of an analogy and it doesn’t literally refer to the type of rotational movement that “spin” more commonly implies.
Each particle has a spin factor that is described by a number, but this is more like a category than a unit of measurement. Those with a spin that is a whole number (integer) are known as bosons.
CERN has now reached the point where ” All the analysis conducted so far strongly indicates spin-zero, but is not yet able to rule out entirely the possibility that the particle has spin-two.”
If it is indeed spin-zero, the particle is a perfect match for the theoretical Higgs boson and the world of astrophysics can celebrate completing the ultimate in jigsaw puzzles: the Standard Model theory that explains, to put it simply, how everything works. The next step after confirming the particle as the Higgs is to see if there’s anything unpredicted about it that means the Standard Model might need tweaking.
If it does turn out to be spin-two, it open up two new questions. Firstly, does the Higgs boson actually exist? Secondly, just what exactly did CERN discover last year? In both cases, one possible answer is that there are actually multiple types of Higgs boson.
Today’s announcement is perhaps best summed-up by Robert Garisto of the Physical Review Letters journal who tweeted “So it may well be a ‘vanilla Higgs’, though there are still hints of unseen sprinkles.”