Charge and fermion number density fluctuations below and above T_c

抄録

Measurement of charge fluctuation and fermion number susceptibilities (isoscalar and isovector) at finite temperatures are attempted on 16×8^2×4 lattice with N_f=2 staggered fermion. In comparison with the previous work on fermion number susceptibilities by Gottlieb et al., new aspect of present study is observation of volume dependence in the fluctuations. Be-low the critical temperature, the charge fluctuations and isovector fermion number susceptibility vary with the volume for V=(2a)^3〜(8a)^3 where a=1/4T. This suggests existence of hadronic length scale in the fluctuations. On the other hand, above critical temperature, fluctuations are almost volume independent for V⪈(2a)^3.