Large Hadron Collider May Have Produced New Matter 238
Covalent writes "The Large Hadron Collider, the world's largest and most powerful particle accelerator and the 'Big Bang machine' that was used to discover what appears to be the long-sought Higgs boson particle (as announced July 4), may have another surprise up its sleeve this year: The LHC looks to have produced a new type of matter, according to a new analysis of particle collision data by scientists at MIT and Rice University. The new type of matter, which has yet to be verified, is theorized to be one of two possible forms: Either 'color-glass condensate' — a flattened nucleus transformed into a 'wall' of gluons, which are smaller binding subatomic particles, or it could be 'quark-gluon plasma,' a dense, soup or liquid-like collection of individual particles."
Re:Do we need a new Mendeleev? (Score:4, Informative)
Not really. The current known elementary particles are all neatly arranged into the Standard Model. The one gap (Higgs boson) was recently filled. What we now need is to discover some process which shows the SM to be incomplete.
Re:New matter (Score:5, Informative)
Both of these conditions have been observed at the Relativistic Heavy Ion Collider (RHIC) in the USA. The CGC was reported in 2003/2004, and the QGP in 2010/2011. So while observing them at LHC is exciting, neither is really "new." LHC's luminosity is much higher than RHIC's, though, so one would expect to be able to study both conditions more readily...
Re:No comments, then a flood of experts (Score:5, Informative)
Let me 'splain. No. There is too much. Let me sum up.
So, when you collide high-energy particles, you get lots of outgoing particles. Sometimes more, sometimes fewer. One thing that you can do to study the outgoing particles is to look at all pairs of tracks in the event (the combinatorics get very large, but you can still do it), and make a histogram of how close together all the pairs were. When you do this, you find that there is a proliferation of tracks that are very close to one another. This is because the outgoing particles tend to come in clusters (we call them "jets"), all moving in approximately the same direction. This happens, more or less, because if you get one outgoing particle with very high energy, but it is an unstable particle, its decay products will tend to be moving in roughly the same direction as the original particle.
Now, you can also do something slightly more sophisticated: instead of just looking at the angle (in any direction) between two tracks, you can use spherical coordinates, and look separately at the angular distance *around* the beamline (azimuth / phi) and the angular distance *from* the beamline (polar angle / theta) (although we actually convert the polar angle into a strange quantity called "pseudorapidity" instead ... this is unimportant for this discussion). When you do that, if you look at events with relatively few outgoing tracks (<35), you see exactly what you expect: an proliferation of tracks that are close in both azimuth and polar angle -- jets again.
On the other hand, if you look at events with lots of outgoing tracks (>= 110), you still see the excess of tracks that are close in both azimuth and polar angle from jets, but you also see a "ridge" -- an excess of tracks that have almost exactly the same azimuth as one another, but have very different polar angles. This is unexpected, and unexpected results == SCIENCE!
So, we expect particles to appear tightly clustered together, but what we see (in some events) is more like a flat spray of particles that goes from one beamline to the other, but is very tightly constrained in one azimuthal slice.
Terrible analogy: We expect cities to occupy a roughly circular area of the earth's surface -- tightly constrained in both latitude (polar angle) and longitude (azimuth). This is like finding a planet that has a city that stretches from pole to pole, but only along a single meridian -- tightly constrained in longitude but totally unconstrained in latitude. It's just plain weird.
Re:Do we need a new Mendeleev? (Score:2, Informative)
So have you missed the 6-sigma confirmation news a couple of weeks after the initial (still un-confirmed) news?
Or did you choose to ignore them?
Re:Why? (Score:5, Informative)
Why are physicists so eager to show the standard model to be lacking? Every few months now we see articles telling how better experiments are confirming the standard model and eliminating some of the alternatives. Just because the standard model isn't new or built on a spiffy new foundation like "string theory" doesn't mean we should want to kill it. In fact, some of those things probably don't deserve use of the term "theory" since they are more complex and haven't been experimentally confirmed in any way (except to the extent they match the simpler "standard model").
Because the standard model does not work for everything. It dose not work well with what we think we know about general relativity.
The assumption is that the universe does not in fact run on 2 differing sets of rules. So it follows that the standard model wile working very well for the things it works for is not in fact true. Even though we believe it to be false it still works really well so we use it.
The standard model though is not a true representation of how the universe really works. We would like to find that.
Re:First post (Score:4, Informative)
It's like discovering nuclear power and wondering what kind of steam locomotive we could build with it.
Odd then, that just about every use of nuclear power is to drive a steam engine/turbine first, and a generator second.
Old tech never dies, it just gets embedded.
Re:New matter (Score:4, Informative)