Attractive Holographic Baryons

We propose a holographic model of baryon interactions based on non-supersymmetric \( {\text{D}}7 - \overline {{\text{D}}7} \) flavor branes embedded in the Klebanov-Strassler background. The baryons are D3-branes wrapping the S 3 of the conifold with M strings connecting the D3 and the flavor branes. Depending on the location of the latter there are two possibilities: the D3 either remains separate from the flavor branes or dissolves in them and becomes a flavor instanton. The leading order interaction between the baryons is a competition between the attraction and the repulsion due to the σ and ω mesons. The lightest 0++ particle σ is a pseudo-Goldstone boson associated with the spontaneous breaking of scale invariance. In a certain range of parameters it is parametrically lighter than any other massive state. As a result at large distances baryons attract each other. At short distances the potential admits a repulsive core due to an exchange of the ω vector meson. We discuss baryon coupling to glueballs, massive mesons and pions and point out the condition for the model to have a small binding energy.