Vector meson mass in the chiral symmetry restored vacuum
Jisu Kim, Su Houng Lee
Abstract
We calculate the mass of the vector meson in the chiral symmetry restored vacuum. This is accomplished by separating the four-quark operators appearing in the vector and axial vector meson sum rules into chiral symmetric and symmetry breaking parts depending on the contribution of the fermion zero modes. We then identify each part from the fit to the vector and axial vector meson masses. By taking the chiral symmetry breaking part to be zero while keeping the symmetric operators to the vacuum value, we find that the chiral symmetric part of the vector and axial vector meson mass is between 550 and 600 MeV. This demonstrates that chiral symmetry breaking, while responsible for the mass difference between chiral partners, accounts only for a small fraction of the symmetric part of the mass.