Talk Talk

[Post reconstructed after 25.10.07 hack]:

dbranesTwo Thursdays ago I went up to Santa Barbara to give a seminar. I had a great time, and it reminded me why it can be so much fun to go somewhere and visit for even a short time and do that. I got to catch up with several old friends, including Santa Barbara itself, where I lived for a number of years in the 90’s when I was a postdoc. I spent time chatting with the various people there before (at lunch) and after (individually) the seminar, learning about some of the research they’re doing, and also talking about other matters physics-wise and gossip-wise. I wish I’d had more time to talk since I did not get to talk to everyone I wanted to talk to, and not at as much length as I would have liked. (This was partly due to the fact that I spent the morning in my hotel room writing some of the slides for my talk. – I had a presentation the day before to focus on, along with a departmental visitor to host, and the day before I was also occupied. Don’t ask about any earlier than that – I never prepare new material that much in advance. Not because I don’t want to, but it just never happens… if I have more than a day or two, I will find that there’s other stuff I have to do.)

Anyway, a good time was had by all (I think). I can even post a picture of some of us at dinner in the evening after the talk. (Will update later with that, since it was downloaded to computer that’s not here.) We went to an old haunt of mine in downtown Santa Barbara – Roy’s. I’m pleased and surprised that it is still there and going strong, since it is the sort of highly individual restaurant that – since it is also reasonably priced – you’d expect to vanish from such a high value spot in town.

What was I talking about? Well, with three students (Tameem Albash, Veselin Filev, and Arnab Kundu), I’ve been involved in some fun work on some of the physics concerning strongly coupled field theory phenomena that I told you about in an earlier post. (We wrote two new papers on it recently. See here and here. ) We’ve been studying the response of quarks (or simple models of quarks) to background electric and magnetic fields, and have uncovered some new phase diagrams and other physics. You can see new phase transitions when the electric field gets so strong that it tears the mesons apart into their constituent quarks, and spontaneous chiral symmetry breaking when the magnetic field gets strong enough (compared to the temperature, which acts to restore the symmetry). Recall that this circle of ideas uses several aspects of string theory to compute physics that may be relevant to aspects of nuclear physics being uncovered in experiments at RHIC (and later to be probed by some experiments at the LHC). All surrounding the properties of the so-called “quark-gluon plasma”, if you recall. See two posts: here and here, for more. The sorts of important “strongly coupled” phenomena we uncover can be modeled and studied closely using the types of stringy computations we carried out.

The slides and audio/video of the talk can be found here.

Enjoy!

-cvj

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6 Responses to Talk Talk

  1. mero says:

    when the electric field gets so strong that it tears the mesons apart into their constituent quarks,

    Now, that’s quite a respectably strong electric field, isn’t it?

  2. Clifford says:

    Strong compared to what? Depends upon the binding energy of the quarks, and what the temperature is. It is easier at high temperature, for example.

    Cheers,

    -cvj

  3. mero says:

    I’d expect that, below the deconfining transition, the binding energy of a quark/antiquark pair is infinite. But a strong enough electric field can create pairs out of the vacuum, breaking the string in the meson and forming more mesons. I guess that’s quite a naive picture but maybe not totally wrong.
    I’d guess that, above the critical temperature for the deconfining transition there are no mesons to break.

  4. Clifford says:

    Sadly, both your expectation and your guess are wrong. The binding energy is finite, and there are mesons above the deconfinement transition. Have a read of the paper and some of the others it cites.

    Best,

    -cvj

  5. Pingback: My work here is done - Asymptotia

  6. Blake Stacey says:

    The sorts of important “strongly coupled” phenomena we uncover can be modeled and studied closely using the types of stringy computations we carried out.

    At this point, I would hardly be surprised if a paper came out applying stringy computations to glass beads. Physics is fun! 🙂