Higgs Boson

From elsewhere:Higgs Boson walks into a church.
Priest says "We don't allow Higgs Bosons in here!"Higgs Boson says "But without me, how do you have mass?"

What is so great about 5 standard deviations?

From my understanding, at 5 sigma there is only a 0.00001% chance that they have not discovered the Higgs boson.

I didn't think statistics applied in particle physics. From what I know about this stuff, particles leave distinct path marks on metal plates after they have gone through an accelerator. I suppose this is a particle that doesn't show one of the same distinct paths that all other known particles have shown?Edited by foreveryoung, : No reason given.

You live and learn.

Particle physics is tied extremely closely to probability. And all science is about degrees of certainty, which is essentially the same as giving a probability that a given hypothesis is accurate.Have you heard of the Uncertainty Principle?Do you understand what an "electron cloud" is?Those might help you understand.

Statistics apply to everything...in any way that you want them to.

Yes I understand both principles. But how do those principles help us know if scorings on a metal plate hit by a bunch of sub atomic particles correspond to certain theoretical particles such as quarks, or muons or bosons or the higgs?

The statistics in particle physics experiments have a simple enough origin in this case.For instance in the case of the search for the Higgs, we see a bump in the two photon channel. This means that around 125 GeV slightly more photons were being produced than the energies around it, the hypothesis is that these extra photons come from the decay of the Higgs boson.However it is possible that extra photons were produced simply by chance without the Higgs. So you compare the results against the scenario where the photons are produced by chance. It then turns out that such a bump has only a 0.00005% chance (1 in 2 million) chance of occurring randomly. Hence it is overwhelmingly likely to be a Higgs.

To me, what the statistics say is that "something" is going on to produce the extra photons that is not random or by chance. Why is it the science community all convinced this "something" is their long sought after higgs boson?

Because the results observed , in the extreme conditions created in the LHC, are exactly the results which the theory predicted would be observed in those extreme conditions, as a result of the existence of the Higgs boson.It's always possible that something else has produced these results - but as people here often say, a scientific theory is the best explanation we can currently find of observed phenomena, and right now, I have not heard of any theory which predicts these results, other than the theory which involves the existence of the Higgs boson. It is therefore the best explanation.(As I understand it, we are, however, only 99.99994% certain.)

If you look at what the scientists have been saying to the press, they're not completely convinced. What they've found is something which in one respect looks like the Higgs boson would look like if it existed. They now want to do more experiments to confirm that it looks like a Higgs boson should look in other respects. So what they said in their press conference was that they've found a "Higgs-like" particle.Now one reason to think it is the Higgs is that if the standard model is right, that would be the last undiscovered boson. But since they are in effect trying to find out if the standard model is correct, they can't use that as a sure basis for saying that it is the Higgs boson, otherwise they'd be guilty of circular reasoning: "The standard model is correct, so we've found the Higgs boson, so the standard model is correct".Hence their cautious use of phrases such as "Higgs-like".

Does a boson of any flavor even have any mass? I don't subscribe to the standard model of particle physics. Bosons are part and parcel of that theoretical system. What is your definition of a particle anyway?

The reasons are as follows:

1. The relation between the width of the bump and the height of the bump produced in the two photon channel matches the Breit-Wigner profile for a decaying relativistic particle.
   
2. The particle is scalar (immediately obvious from the channel it was discovered in) and carries no spin, the Higgs has spin-0
   
3. The particle has weak isospin of 1/2, just like the Higgs is expected to.
   
4. It was found inside the expected mass range of the Higgs
   
5. It has decay rates in other channels (decaying into leptons, e.t.c.) at the rate expected of the Higgs.
   

Now as Dr. Adequate has said you will still see people say that the particle is "Higgs-like" or "a Higgs". This is because the Higgs is a particle produced after the Electroweak Force broke into the Electromagnetic and Weak Nuclear Forces. However, depending on what exact mechanism separated the forces the Higgs will be slightly different, even though it will always obey the points 1. - 5. above.The simplest mechanism is the one proposed by Higgs, Anderson, Englert, Brout and Kibble back in the 1970s. This version of the Higgs is usually known as "the Higgs" or "the Standard model Higgs".Other mechanisms produce slightly different Higgs bosons, sometimes called "Higgs-like" or "a Higgs".The main aim now is to find which one of the four candidate mechanisms is true (a fifth one has already been ruled out and there aren't others because these are really the only ideas consistent with quantum field theory).Edited by Son Goku, : No reason given.Edited by Son Goku, : Editing

Several bosons have mass. The W bosons, the Z bosons, the eta meson, the eta prime meson, there are hundreds. A boson is any particle whose spin (a measure of how much the particle is rotating about its axis, if you want a classical picture) is a whole number. For what reason? The proper definition of a particle is very abstract and requires some background exposition in quantum mechanics. I can do so, if you wish.