Validity of the Balázs Method

A systematic study of the Balázs method, as applied to the ρ-bootstrap problem in the 2π system, is made in order to determine its validity. Inelastic effects as estimated from Regge theory are included. We find that the method becomes well-behaved as the number of poles used to approximate the left-hand cut is increased, in contrast to results obtained previously by Bond, and that the sensitivity of the solutions to the choice of matching point may be largely eliminated by a procedure proposed by Williamson and Everett. The method predicts a ρ mass of somewhere between 680 and 760 MeV as compared to the experimental value of 750±25 MeV, and a ρ half-width of about 150 MeV as compared with the experimental value of about 50 MeV.