Quark Soup Al Dente

Here’s Rob Myers in action, giving Monday’s excellent departmental colloquium, entitled “Quark Soup Al Dente: Applied String Theory”:

robert c myers quark soup al dente

Here was his abstract:

In recent years, experiments at the Relativistic Heavy Ion Collider have discovered an exotic new state of matter known as the quark-gluon plasma. Simple theoretical considerations suggested that this plasma would behave like an ideal gas, however, the experiments show that it actually behaves very much like an ideal liquid. Thus the standard theoretical tools, such as perturbation theory and lattice gauge theory, are poorly suited to understand this new phase. However, recent progress in superstring theory has provided us with a theoretical laboratory for studying very similar systems of strongly interacting hot non-abelian plasmas. This surprising new perspective extracts the fluid properties of the plasma from physical processes in a black hole spacetime. At present, this approach seems to provide some of the best tools which theoretical physicists have to understand the heavy ion collisions at RHIC.

For a very good blog post on this issue, see Bee and Stefan’s post at Backreaction.

It was really excellent to see Rob and spend some time with him at dinner afterwards and at lunch the next day with my students. We got to chat over a nice Tapas-style meal and catch up a bit on what each other has been up to (both in and out of physics – Rob is one of my most long standing friends and collaborators in the field), and he even gave us a seminar on Tuesday before leaving.

Now, here’s a physics question for you:

Any ideas why he chose “Quark Soup Al Dente”? There’s a very good and interesting physics reason. Let me hear your thoughts on this in the comments, if you like. I’ll update this post later on with the answer.



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13 Responses to Quark Soup Al Dente

  1. Andy says:

    My guess:

    Soup = the liquid “broth” of quarks and gluons
    Al dente = the “softly interacting” (but not too softly!) interacting strings inside the soup that give it its viscosity.

  2. Bee says:

    Hi Clifford,

    thanks for the link. I recall a seminar I heard by Rob Myers last summer. When the first question was asked in the end he made some really funny faces and then said: “I’m disappointed by the question, because it means I didn’t bring anything across.” This was probably the most honest answer I’ve ever heard someone giving in a seminar 😉

    Something completely different: have you heard the MiniBoone results? I can’t really find anything sensible about what they have actually measured. Will you write a post on it?



  3. Clifford says:

    Bee: – I must be out of the loop. I have not heard anything. Please let me know.

    Anyone know anything about MiniBoone?


  4. Scott H. says:

    Anyone know anything about MiniBoone?

    Jocelyn Monroe just gave a colloquium on the MiniBoone results today. It was a fantastic talk — anyone who wants to get an overview from an expert should invite her! I’m not even approximately an expert on this subject and am essentially just trying to regurgitate what I learned from her talk, from memory.

    One of the major motivations of MiniBoone was trying to understand the LSND result, which indicated an excess of oscillations into electron neutrinos. One possible interpretation of their result was that there exist sterile neutrinos, and that the excess of electron neutrinos in their beam was due to oscillations of sterile neutrinos. This would be one hell of an exciting result if true, so people have been pretty eager to test it.

    Hence MiniBoone. MiniBoone makes a beam of muon neutrinos, sends it through half a kilometer of dirt, then dumps the beam in a tank of mineral oil (which is outfitted with a gajillion phototubes). Some of the muon neutrinos oscillate into electron neutrinos en route. The various interactions of the different neutrino flavors with the target produce signatures which they measure in their phototubes; by understanding those things, they can measure the oscillations into electron neutrinos.

    Jocelyn’s talk was devoted hugely to the details of how the backgrounds are understood and the data are analyzed. It was impressive. Jocelyn was deeply involved in this process and did a really thorough job going over everything.

    The punchline: NO excess. I can’t even say no “significant” excess; there just wasn’t any. They cannot explain the LSND result. (It’s worth mentioning that a good fraction of the MiniBoone team is also associated with LSND — quite an honest approach, it seemed to me.) It remains a mystery what is going on with the LSND data; but, MiniBoone seems to be pointing to a fairly standard result for neutrino oscillations. No sterile neutrinos needed, it would seem.

    Take all the details with a grain of salt — the punchline was clear, but this is rather far from my expertise, so I’m likely to be botching things.

  5. Kea says:

    Al Dente probably refers to the correct Ribbon-like calculus, as opposed to skinny lines.

  6. Pingback: MiniBooNE for Neutrinos - Asymptotia

  7. Plato says:

    Scott:It remains a mystery what is going on with the LSND data; but, MiniBoone seems to be pointing to a fairly standard result for neutrino oscillations. No sterile neutrinos needed, it would seem.

    I’m crushed 🙁

    Somebody better tell Symmetry Magazine?

    For example, when neutrinos interact with matter they produce specific kinds of other particles. Catch the neutrino at one moment, and it will interact to produce an electron. A moment later, it might interact to produce a different particle. “Neutrino mixing” describes the original mixture of waves that produces this oscillation effect.

    Current evidence shows that neutrinos do oscillate, which indicates that neutrinos do have mass. The Los Alamos data revealed a muon anti-neutrino cross over to an electron neutrino. See here

    So while there is no need for the “sterile neutrino” does this invalidate the oscillation process and whether this invalidates that neutrinos have mass?

  8. Plato says:

    the quark-gluon plasma behaves according to hydrodynamic calculations in which the matter is like a liquid that flows with no viscosity whatsoever.” See here

    No cross over point? What role would Navier Stokes play in this?

  9. Aaron F. says:

    Plato — I know nothing about this, but I think the MiniBoone result actually supports the standard picture of neutrino oscillations, where neutrinos are continually changing between the three known flavors: tau, muon, and electron.

    It’s my understanding that if the LSND result had held up, it could have been evidence for sterile neutrinos: neutrinos that don’t participate in the weak interaction. Since ordinary neutrinos participate only in the weak and gravitational interactions, sterile neutrinos would interact only with gravity, making them practically impossible to detect directly.

    Somebody correct me if I’m wrong!

  10. Elliot says:


    This is described in complete detail over at CV. Basically Neutrinos still oscillate and have mass but the LSND results suggesting something wrong with the standard model are contradicted.

  11. Paul Valletta says:

    Al Dente?

    Ok the “strings” are “spagettified” into a multi_entangled consistancy, much like the effect of “spagettification” first introduced in Black Hole “input_output” theories?

    Maybe there is an artist out there who can produce a picture of a “War_hole” type, canned_quark_soup ? 😉

    Helium droplets, are theorized to be in a solid (canned) state, but give out liquid properties, such as BEC.

    Thus I conclude :Al Dente = condensate spaghetti soups 😉

    Best pv.

  12. Plato says:

    Thanks Aaron and Elliot,

    Paul:Maybe there is an artist out there who can produce a picture of a “War_hole” type, canned_quark_soup ? 😉

    Entanglement issues on the horizon, Paul?

    Soup is Physical Spacetime, Label is…?

    See: Spacetime in String Theory by Dr.Gary Horowitz, Apr 20, 2005

    After reviewing the properties of spacetime in general relativity, I will provide an overview of the nature of spacetime emerging from string theory. This is radically different from relativity. At a perturbative level, the spacetime metric appears as “coupling constants” in a two-dimensional quantum field theory. Nonperturbatively (with certain boundary conditions), spacetime is not fundamental but must be reconstructed from a holographic, dual theory. I will conclude with some recent ideas about the big bang arising from string theory.