F.F. I decided to let my cat Higgs write this one since he's an avid follower of high energy physics.
Higgs: Hi. Higgs here. I would bet anyone a whole bag of Friskies' salmon flavored cat treats that scientists will announce a discovery of the long-sought Higgs boson on July 4. The salmon ones are the best – treats that is. Subatomic particles come in weird flavors such as "strange" and "charm".
Why am I so sure of myself about the Higgs? Well, the timing of the announcement is not entirely determined by the science – it also requires a decision by the humans involved in the search. The physicists don't see the Higgs directly but construct a statistical argument out of a lot of Higgs tracks.
This morning we got a press release from CERN, the European physics lab where scientists are trying to make Higgs particles materialize in a particle-smashing machine called the Large Hadron Collider. The release said they were going to announce something important related to the Higgs on the Fourth of July.
The Higgs is the last missing piece in the current theory of matter and the forces that govern it.
This will be big news here in Philadelphia, since 27 physicists from Penn have been working hard to find the Higgs. The Higgs is not something you can discover directly, the way astronomers found Neptune and Pluto. This is not like a new species of frog that you can put in a bag.
The Higgs is unstable in ordinary conditions so once a Higgs materializes, it instantly disappears. Luckily, it leaves behind a burst of other particles, some of which leave trails through various materials. Scientists take pictures of these trails in two rather large detectors positioned around the 17-mile ring that make up the collider.
The Penn team works with a detector called Atlas. The other one is called CMS. It's good to have two independently-run detectors, since this allows independent confirmation of the science without having to build another 17-mile apparatus.
Penn professor Brig Williams explained that there are three major patterns of debris that are likely to be left behind by the Higgs. One possible Higgs track entails two high energy photons. The other two involve pairs of exotic particles called W and Z, which themselves spontaneously disappear and become more commonplace particles that speed through the detectors. The problem is that any of these signals could show up without a Higgs ever gracing their experiment.
If you were looking for me and you found some orange fur, you couldn't be sure it was mine. It might be some other orange cat.
So what the physicists do is they gather a lot of data. The more data they have the lower the odds that they're seeing a coincidental convergence of Higgs imposters. Last December they had collected enough potential Higgs candidates to reduce their odds of a false sighting to one in a thousand. That sounds good, said Williams, but back then, they were hunting for an unexpected signal over a large range of energies, so the odds are not so remote that something weird would crop up somewhere.
Now they're looking for something more specific since they've narrowed down the mass of the possible Higgs. After looking more closely in a narrow range, they probably either confirmed the Higgs at that mass or ruled it out. What they really want is less than a one in a million chance they've seen a statistical fluke, but they might announce a discovery with somewhat less statistical power.
Dr. Williams says if it is a discovery there will still be plenty of science to do to study the Higgs. And the LHC might produce other hitherto unknown high energy particles in the future.