# Strong chiral symmetry (SSB?)

by ChrisVer
Tags: chiral, strong, symmetry
 P: 855 Why is the chiral symmetry breakdown determined for the vector/axial current as: $V = \frac{m_{π^{+}}-m_{π^{0}}}{m_{π^{0}}+m_{π^{+}}}\approx 0.01$ $A= \frac{m_{π^{+}}-m_{f^{0}}}{m_{f^{0}}+m_{π^{+}}}\approx 1$ ? why do we choose the difference between the pion+ (~140MeV) and pion0 (~135MeV) for the vector current or the difference between the pion(~140MeV) and the f0 meson (~900MeV) for the axial? Also why take that formulas for those asymmetries?