Meson melting and chiral symmetry restoration in improved holographic QCD

We study light meson melting in a soft-wall holographic QCD model. The model includes a dilaton field that describes confinement and a scalar field dual to the chiral condensate. These fields are coupled in this work, yielding a critical point in the chiral phase diagram.



We numerically compute the spectral function of vector and axial mesons identifying spectral peaks as bound states. Due to chiral symmetry breaking, the axial spectral peaks are located at a higher mass than the vector spectral peaks. As temperature increases, chiral symmetry is restored, causing the axial spectral peaks to tend towards the same values as the vector spectral peaks. Additionally, temperature increase leads to peaks vanishing, beginning with excited states. We discuss the sequence of the restoration of chiral symmetry and the melting of mesons to determine if chiral symmetry is restored prior to melting.