A Comparison of different measures for dynamical event-mean transverse   momentum fluctuation
  Various measures for the dynamical event-mean transverse momentum fluctuation are compared with the real dynamical fluctuation using a Monte Carlo model. The variance calculated from the G-moments can reproduce the dynamical variance well, while those obtained through subtraction procedures are approximate measures for not very low multiplicity. The Phi_pt can also serve as an approximate measure after divided by the square root of mean multiplicity. 
Liu Lianshou and Fu Jinghua