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Institute for the Physics and Mathematics of the UniverseWPI

String theory and QCD

Confirmed speaker: Shigeki Sugimoto
Date: Oct 30, 5 pm, Main Seminar Room, 6th floor, ICRR
  Recently, we proposed a holographic description of 4 dim QCD by using a D4/D8-brane system in type IIA string theory. (hep-th/ 0412141 with T. Sakai) It has been shown that the model nicely catches a lot of features of QCD and hadron physics. For example, the chiral symmetry breaking in QCD is easily understood from the geometry of the background. Mesons (such as pions, rho mesons, a1 mesons) are beautifully unified in a five dimensional gauge field. We can explicitly calculate the effective action of these mesons and it is shown that the structure of the interaction is consistent with various phenomenological models. Furthermore, the masses and couplings are roughly in good agreement with the experimental values, although the approximation used in our analysis is still crude. Baryons are constructed as instantons in a five dimensional gauge theory and the baryon spectrum is obtained by considering a quantum mechanics on the instanton moduli space. (Refs: hep-th/ 0412141, 0507073, 0701280) Focus Weeks