Hunting the Higgs
Today is a big day for the physics community, and possibly a day that will be remembered forever in history by scientists in general. Sometime today (around midnight locally) there will be a lecture by the two teams of particle physicists who are searching for the Higgs boson at the Large Hadron Collider. With the LHC running at full power now and the search in full gear, the rumors are that they have indeed discovered the elusive Higgs.
I have written about the Higgs
mechanism and Higgs boson several times in this blog and others, so I
won't give a full review here. The short summary is as follows
though:
Fifty years ago physicists had
developed a Standard Model of particle physics, which was able to
explain all known particles using symmetry laws and experimental
data. The problem though, was that the symmetry laws which generated
the electromagnetic and weak nuclear forces required massless
particles, and the experiments indicated very heavy particles.
The solution that was devised was the
Higgs mechanism. All particles were assumed to be massless, but then
another particle/field is added which fills the entire Universe, and
which in many ways acts as a thick fluid that slows everything down.
This slowing down makes it appear as though the particles have a
mass, but doesn't violate the symmetry properties that the Standard
Model required.
Except no one could ever detect the
elusive Higgs field. Since it has the same properties everywhere in
the Universe, and since it is invisible, it cannot easily be studied.
The one exception is if you could change its density in a small
region – add a little more Higgs field in some region and the
difference between it and other regions tells you what the Higgs'
properties are.
For fifty years scientists have been
hunting the Higgs, and many textbooks have been written just to
explain possible methods of finding it. The rest of the Standard
Model was detected and confirmed decades ago. Many billions of
dollars were spent by the international community to build particle
accelerators whose main goal was to find the last piece of the
puzzle. After so many failed experiments, theorists were starting to
generate mountains of academic papers giving possible alternatives to
the Higgs model. Finding the Higgs boson has become the holy grail of
particle physics.
And if the rumors are true, then
tonight the LHC will be announcing exactly that. They are keeping it
very secret right now, but everything points to success tonight. And
perhaps tonight, physics history will be made...
(Watch it live here)
PS: As a side note, I have also had a few people ask about the Higgs' nickname of 'God Particle'. This was a term invented in the early 1990s by a publisher to hype a popular physics book, and really has no meaning. The Higgs boson is a major discovery for the physics community, but it has no connection at all to religion or deities.