Holographic Deuteron and Nucleon-Nucleon Potential

Abstract

We compute the potential between a pair of nucleons in the D4-D8 holographic QCD. In the large 't Hooft coupling limit, $λ\gg 1$, the hadronic size of the baryon is small $\sim 1/\sqrtλM_{KK}$, and their interaction with mesons are well approximated by a set of dimension four and five operators. The nucleon-nucleon potential emerges from one-boson exchange picture involving massless pseudo-scalars and an infinite tower of spin one mesons. We find in particular that $ρ$ meson exchanges are dominated by a dimension five derivative coupling of tensor type, whereas for $ω$ mesons and axial mesons, such tensor couplings are completely absent. The potential is universally repulsive $\sim 1/r^2$ at short distance, and has the usual long-distance attractive behavior $\sim -1/r^3$ along a isosinglet and spin triplet channel. Both the large $N_c$ form and the finite $N_c$ form are given. In the former, a shallow classical minimum of depth $\sim 0.1M_{KK}{N_c/λ}$ forms at around $rM_{KK}\simeq 5.5$.

33 pages, 4 figures, a preprint number added, typos fixed, a reference added, a minor revision in section 5.3