Baryonic condensates on the conifold

We provide new evidence for the gauge/string duality between the baryonicbranch of the cascading SU(k(M+1)) \times SU(kM) gauge theory and a family oftype IIB flux backgrounds based on warped products of the deformed conifold andR^{3,1}. We show that a Euclidean D5-brane wrapping all six deformed conifolddirections can be used to measure the baryon expectation values, and presentarguments based on kappa-symmetry and the equations of motion that identify thegauge bundles required to ensure worldvolume supersymmetry of this object.Furthermore, we investigate its coupling to the pseudoscalar and scalar modesassociated with the phase and magnitude, respectively, of the baryonexpectation value. We find that these massless modes perturb theDirac-Born-Infeld and Chern-Simons terms of the D5-brane action in a wayconsistent with our identification of the baryonic condensates. We match thescaling dimension of the baryon operators computed from the D5-brane actionwith that found in the cascading gauge theory. We also derive and numericallyevaluate an expression that describes the variation of the baryon expectationvalues along the supergravity dual of the baryonic branch.Comment: 34 pages, 1 figure; v2 typos corrected, references added; v3 added comment on \kappa-symmetry of Euclidean D5-brane, published in JHE