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New Type of Particle May Have Been Found
An anonymous reader writes "The LHC is out of commission, but the Tevatron collider at Fermilab is still chugging along, and may have just discovered a new type of particle that would signal new physics. New Scientist reports that the Tevatron's CDF detector has found muons that seem to have been created outside of the beam pipe that confines the protons and anti-protons being smashed together. The standard model can't explain the muons, and some speculate that 'an unknown particle with a lifetime of about 20 picoseconds was produced in the collision, traveled about 1 centimeter, through the side of the beam pipe, and then decayed into muons.' The hypothetical particle even seems to have the right mass to account for one theory of dark matter."
The New Scientist article points to a paper at arxiv:
http://arxiv.org/abs/0810.5357
with the rather less sensational title:
Study of multi-muon events produced in p-pbar collisions at sqrt(s)=1.96 TeV
I'm amused to note that the author list stretches over three pages, which I gather is common for this sort of paper.
John Conway talks about this over at Cosmic Variance: http://cosmicvariance.com/2008/11/02/cdf-ghost-muons/
Not to ask the blatantly obvious, but if it's the right mass for one theory of dark matter, I can't help but wonder where they are all being produced. Given a life of 20 picoseconds, I can't imagine that there would be monstrous factories of these things all over the universe to account for the stupidly large amount of mass they are supposed to account for. How come we haven't found them before?
I thought the same thing at first, but the article states that they are theorizing that the particle produced is not a dark matter particle itself, but rather the particle that carries forces between dark matter particles. It is entirely possible that there are stable dark-matter particles, but for the force-carrying particles to be unstable when produced in isolation.
The Tevatron is big money science. the LHC is bigger money science.
upon the advice of my lawyer, i have no sig at this time
That's because it takes a lot of electricity to cool the collider down. Europeans like to use a lot of electricity to keep their buildings warm in winter, which drives up the price of electricity. So they wait for summer when electricity is cheaper and the giant German solar panel farms are pumping out lots of jiggawatts.
More than possible. Of the force carrying particles we know of, only the photon is stable. The graviton, if it exists, should be stable. But the W+/-, Z and all the various flavours of gluons are unstable.
The real stuff has gotten pretty tough. I had the challenge once to rework a preproduction board to prove a design change. I was way out of my comfort zone.
Resistors these days are the size of a juvenile flea. If you drop one, let it go man... it's gone. ICs aren't much better. You have to use IPA and a lintfree cloth just to clean the soldering tweezers. It takes a 60x microscope and a steady hand. I was really regretting my caffeine habit. And the tiny static charges make everything sticky. The leadfree solder takes more heat so you have to be extra careful not so bake the components to death. And don't stab yourself with the tweezers. They look like pencil erasers in the scope but they'll penetrate your skin with no resistance, burning the whole way.
It worked. It wasn't pretty, but it worked. I am thrilled to have had the experience. I wish I knew a vendor for the surgical point soldering tweezers.
Respect to the asian ladies in the factory that do this all day for a pittance, with nothing more than a magnifying glass and grim determination.
Help stamp out iliturcy.