The most important discovery in particle physics in the past 40 years was announced last July 4th. The long-sought Higgs boson was discovered. This diary is to update you all on the current status and future prospects.
Two years ago (July 2011), I posted a diary here describing the beginning of the search at the Large Hadron Collider (LHC), at CERN in Geneva, followed up with a couple of other diaries over the next few months and then finally posted a diary here on "discovery day" a year ago. I was very gratified by the response - far above anything I expected.
You will not learn what the Higgs boson is in this diary. For a brief discussion, go to the "discovery day" diary, and for a more substantial introduction, go to the first diary linked above. In the earlier diaries, I explained that the Higgs field is responsible for the masses of all fundamental particles, and that without the Higgs field, the laws of physics would be much simpler. Recently, I did hear (in an article by a friend, Frank Wilczek) of another analogy that might explain why this discovery is so much more important than just the discovery of "a new particle".
Imagine a planet composed entirely of water. A fish civilization develops and begins to learn about chemistry and physics. Since the water is always around them, they don't even know it is there. They would find that something as simple as the laws of motion would be incredibly complicated -- boxlike fish would move more slowly, torpedo like fish would move more quickly, some fish drift down, dead fish drift up, etc. It would seem to be a mess. Then a very smart fish, Fish Newton, makes a suggestion. Suppose there is a substance everywhere called "Ocean". All of inertia is due to the interaction of objects with Ocean. If Ocean were to completely disappear, the laws of physics would become incredibly simple. Fish Newton would propose that if you could put a lot of energy into a small volume, you might shake loose a molecule of Ocean, and in that way detect its presence. That would be the "Ocean boson".
The Ocean is the Higgs field. While the Higgs boson isn't exactly the same as a "molecule" of Higgs field (no analogy is perfect), it does represent direct evidence that the Higgs field is real.
The discovery a year ago today established that there really is an Ocean. The Ocean is real. This is hugely important for our understanding of Nature.
A description of the current status of the Higgs, and of prospects for the future, is below the Great Orange Croissant.
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