I’ve been meaning to write a quick note thanking people for their comments on last week’s post about tracking. When I spend a lot of time on making sure a post really explains something well, it means a lot to me to know that my effort succeeded. (A note to readers who happen to be my advisor: I didn’t spend too long on it, I swear. And anyway I was waiting for my code to compile.) So, thanks! While I’m here, I figure I might as well share an observation that occured to me while reading the comments, and then answer a question that was asked.
First the observation. In my experience, if you go to a baseball game and point out that the people on the other side of the stadium “look like” a particle tracker for the ball, your friends stare at you as if you’re crazy. And yet, if you write about particle physics and manage to compare it to baseball, then it goes over rather well as a feat of science explication. I conclude from this that the trick to being a tremendous nerd while still being cool is to manage expectations; get your audience to expect you to be an even bigger nerd than you actually are, and they’ll be impressed.
Second, the question: Didi Mouse asked who gets to name any new particles we find. The answer is that we don’t actually know yet, but it depends on what’s out there. Many particles — for example, the Higgs boson — have been named already; if we make a discovery that looks more or less like a Higgs boson, we’ll call it a Higgs boson. There are also theories that predict lots of new particles; often those particles are all named, but according to some regular rule. For example, Supersymmetry predicts a new particle for every known fundamental particle. The superpartners have the same name as the original, but with an “s” in front for some spins, and an “ino” at the end for others; electron becomes selectron, quark becomes squark, photon becomes photino, gluon becomes gluino, and (my favorite) W becomes Wino. If we were sure we’d found Supersymmetry, we’d probably keep those names, but we won’t be sure at first what new theory the particles we’ve found fit into — so what will we do? I expect the decision will be made as part of the experimental collaborations’ processes for writing and approving papers, because the name for a new particle usually comes from the paper that announces the discovery. As far as I know, nobody has specific plans for how to handle the naming, but it is a problem we will be delighted to have.
Tags: baseball analogy, culture, Higgs, outreach
Speaking of names….
I would like to suggest the word ‘supermatter’ as a generic name for all of the supersymmetric particles. (Of course, supersymmetric particles should really be called supersymmetric partners of known particles, since supersymmetry is a proposed symmetry,).
But ‘supermatter’ sounds good and hints at a nice parallel with antimatter (we were lucky the positron was found so early on).
From my perspective, the only reason to be hesitant about that term is that sparticles (i.e. supersymmetric particles) never really act like regular matter, because they’re so much heavier — and so will decay almost instantly, except possibly for the lightest one, which could be dark matter. Antimatter, by contrast, acts almost exactly like matter, if you can keep it away from all the matter that surrounds us here on earth. For example, I have friends from Berkeley who work here at CERN to make atoms of anti-hydrogen — i.e. an antiproton and a positron bound together — and keep them from being destroyed long enough to look at them. It’s never been done before, and it’s very difficult work, but in principle we expect such an atom to behave just like a regular hydrogen atom when it’s isolation.
Yes, I agree – but can’t one argue that the mass difference of supersymmetric partners (if they exist) form ‘normal’ matter is a consequence of broken symmetry, just as the slight difference in decay of antimatter vs matter is a consequence of symmetry breaking (CP violation etc)?
In other words, the diffrence in mass of SUSY is a difference of degree, rather than fundamental. It’s worth recallling thaat no-one (incl Dirac) believed in antimatter at first…
I think we agree that the comparison is quite valid on the level of fundamental physics, but breaks down in terms of phenomenology because of the large mass splitting. It then becomes a question of taste: I personally would like to define “matter” as “particles that stuff is made out of” in order to main a connection with the layperson’s common-sense definition of the word. But that would imply that a top quark isn’t “matter” either… what a mess!
hi
I like to learn more elementary particls acceleratore.
thanks
bye.
Hi Mehdi,
This video made by CERN is a very good place to start:
http://www.youtube.com/watch?v=m2nu-K5GEPg
It describes all the stages that particles go through in the accelerators here at CERN, up to and including the Large Hadron Collider.
Everyone is invited to attend an ongoing CERN LHC/ALICE/ATLAS Public Opinion Debate Forum in progress, through the following direct-link provided:
http://www.volconvo.com/forums/science-technology/22661-cern-lhc-alice-atlas.html
Thank you for you participation in this educational endeavor!
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Robert Marsh II / THE FIFTH KNIGHT