Matrix model and holographic baryons in the D0-D4 background

Abstract

We study on the spectrum and short-distance two-body force of holographic baryons by the matrix model, which is derived from Sakai-Sugimoto model in D0-D4 background (D0-D4/D8 system). The matrix model is derived by using the standard technique in string theory and it can describe multi-baryon system. We re-derive the action of the matrix model from open string theory on the wrapped baryon vertex, which is embedded in the D0- D4/D8 system. The matrix model offers a more systematic approach to the dynamics of the baryons at short distances. In our system, we find that the matrix model describe stable baryonic states only if $\zeta=U_{Q_{0}}^{3}/U_{KK}^{3}<2$, where $U_{Q_{0}}^{3}$ is related to the number density of smeared D0-branes. This result in our paper is exactly the same as some previous presented results studied on this system as \cite{key-24 Baryons in D0-D4}. We also compute the baryon spectrum ($k=1$ case) and short-distance two-body force of baryons ($k=2$ case). The baryon spectrum is modified and could be able to fit the experimental data if we choose suitable value for $\zeta$. And the short-distance two-body force of baryons is also modified by the appearance of smeared D0-branes from the original Sakai-Sugimoto model. If $\zeta>2$, we find that the baryon spectrum would be totally complex and an attractive force will appear in the short-distance interaction of baryons, which may consistently correspond to the existence of unstable baryonic states.