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Scientists Have Detected a New Particle At the Large Hadron Collider At CERN (bbc.com)
New submitter ag144 writes: First time witnessed, the Large Hadron Collider finds predicted double-heavy particle. BBC reports: "Nearly all the matter that we see around us is made of neutrons and protons, which form the centers of atoms. These are made up of three smaller particles called quarks which can be either light or heavy. There are, however, six different types of quarks which combine in different ways to form other kinds of particle. Those that have been detected so far contain at most, one heavy quark. This is the first time that researchers have confirmed the existence of one with two heavy quarks. The research team will now measure the properties of the Xi-cc++ to establish how this new arrangement of quarks behaves and how the strong force holds the system together. They also expect to find more double heavy quark particles. Another unusual property of the particle is that it has two positive charges double that of the proton and it is four times heavier."
Quarks come in three "generations". The first, lightest generation has down (mass 4.8 MeV) and up (mass 2.4 MeV). The second generation has strange (95 MeV, a heavier version of down) and charm (1275 MeV, a heavier version of up.) The third generation has bottom (4180 MeV, heaver version of down and strange) and top (172440 MeV, heaver version of up and charm.)
When they combine into particles, you either get paired quark+anti-quark (e.g. up+anti-down is a pi+ particle) or a triple of same type: quark+quark+quark or anti-quark+anti-quark+anti-quark. (E.g. a proton is up+up+down.)
This article says the new particle has two charm quarks.
This article says Xi baryons are a class of particles which have a single up or down plus two more massive quarks: either strange, charm or bottom, and Xi baryons have been known since 1952.
From this I conclude that when they say "light" quarks they mean down, up and strange. (I was very frustrated that they didn't say what they meant by "light" quarks.)
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According to
http://www.zeit.de/wissen/2017-07/cern-teilchen-baryon-lhc-teilchenbeschleuniger-genf-physik
the particle, called Xi cc++ lasted for 0.0000000000005 seconds.
Philipp
I know you guys are excited about all this cool stuff but it won't be long until they cause a triple heavy quark particle to emerge and it's game over. I know you guys like to have fun with the "universe" but you're effectively about to cause a memory rehash which the system can't handle. To be honest, I blame myself for this. I mean, when I was constructing this sim, I skimped on memory thinking that 640 zettaquads ought to be enough for everybody. ;)
Anons need not reply. Questions end with a question mark.
The top quark has a lifetime on the order of 10^-25 seconds, so short they don't hadronize. So doubt there's any chance we'll make tt particles.