The dropping of in-medium hadron mass in holographic QCD

We study the baryon density dependence of the vector meson spectrum using the D4/D6 system together with the compact D4 baryon vertex. We find that the vector meson mass decreases almost linearly in density at low density for small quark mass, but saturates to a finite non-zero value for large density. We also compute the density dependence of the eta' mass and the eta' velocity. We find that in medium, our model is consistent with the GMOR relation up to a few times the normal nuclear density. We compare our hQCD predictions with predictions made based on hidden local gauge theory that is constructed to model QCD.This work was supported by the WCU project of Korean Ministry of Education, Science and Technology (R33-2008-000-10087-0). This work is also supported by the Mid-career Researcher Program through NRF Grant No. 2010-0008456 and by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (No. 2005-0049409)