Relating the pion decay constant to the chiral restoration temperature
  We review the relationship between the pion decay constant $f_\pi$, the chiral symmetry restoration temperature $T_c$ and the phenomenology of low energy chiral symmetry breaking in view of the recent confirmation of the existence of a sigma meson with a mass of 600-700 MeV. 
N. Bili\'c, J. Cleymans and M.D. Scadron