Baryonic States in QCD From Gauge/String Duality at Large Nc

摘要

We have computed the baryon spectrum in the framework of (Nu) = 4 super-conformal Yang-Mills theory using AdS/CFT duality. Baryons are included in the theory by adding an open string sector, corresponding to quarks in the fundamental representation of (Nu) = 4. The hadron mass scale is introduced by imposing boundary conditions at the AdS(sub 5) coordinate r(sub 0) = (Lambda)(sub QCD) R(sup 2), which is the only parameter. The quantum numbers of each baryon, are identified by matching the fall-off of the string wavefunction (Psi)(x,r) at the asymptotic 3+1 boundary to the operator dimension of the lowest three-quark Fock state, subject to appropriate boundary conditions. Higher Fock states are matched quanta to quanta with quantum fluctuations of the bulk geometry about the AdS background. We limit our discussion to massless quarks. The resulting four-dimensional spectrum displays a remarkable resemblance to the physical baryon spectrum of QCD, including the suppression of spin-orbit interactions.