The Discovery of Higgs Boson
The news this morning out of CERN is genuinely exciting. After years of searching for it, and few previous teases, the scientists have finally confirmed the discovery of a new particle that looks like the elusive "Higgs Boson." This is the first major discovery of a new particle in decades, and if it indeed proves to be THE Higgs Boson, its significance could not be understated. It would be the discovery of the final Lego block in the theoretical model of all (well, almost) fundamental particles and fields. With it, the Standard Model of particle physics, the crowning jewel of all of the 20th century research in particle physics, will finally be complete and stand on completely solid experimental grounds.
The news this morning out of CERN is genuinely exciting. After years of searching for it, and few previous teases, the scientists have finally confirmed the discovery of a new particle that looks like the elusive "Higgs Boson." This is the first major discovery of a new particle in decades, and if it indeed proves to be THE Higgs Boson, its significance could not be understated. It would be the discovery of the final Lego block in the theoretical model of all (well, almost) fundamental particles and fields. With it, the Standard Model of particle physics, the crowning jewel of all of the 20th century research in particle physics, will finally be complete and stand on completely solid experimental grounds.
The reason that Higgs Boson is so significant is that it underlies our understanding about one of the most fundamental aspects of elementary particles: why they have mass. In classical physics particles could in principle have any mass. The Standard Model, on the other hand, deals with an exactly enumerated number of different particles, each of which has a very specific mass. In most cases those masses can be thought of as a simple parameter, something that you put in by hand into the equations to make them work for that particular particle. However, when the issue of the masses of weak interaction particles came up (for the so called W and Z bosons), the simple put-in-masses-by hand way of dealing with them could not be applied. This has to do with some arcane mathematical properties of the interaction particles, which makes it impossible for them to have the "normal" kind of mass. The way out of this difficulty was discovered by postulating a new way of acquiring mass, the now eponymous "Higgs Mechanism." This mechanism postulates the existence of a new kind of field (Higgs Field) which by interacting with all other particles gives them mass. This was a brilliant solution to a very difficult theoretical problem, but it required the introduction of a whole new field, hence the Higgs field and Higgs boson. Higgs field made the whole edifice of Standard Model work, but until now its existence has not been much more than a neat trick.
The today's announcement comes with many qualifications. The discovered particle is definitely a boson (a particle with an integer value of spin), but what kind of boson it's not clear. It is also not clear that it really is Higgs boson, and much further research is needed to confirm this. Furthermore, from what we've seen so far the kind of Higgs that this particle would correspond to does not give us any hints about the physics beyond the Standard Model. This may be very disappointing to many, since the Standard Model, effective as it is, is still just a very loosely connected set of rules and theoretical constructs that holds it all together. It's sort of like the periodic table before the discovery of quantum mechanics. Finding the fundamental theory behind the Standard Model remains one of the longest standing and most elusive goals in Physics. And unfortunately, we are no closer to the fulfillment of that goal today than we were half a century ago when the Higgs mechanism was first proposed.