0 v 1 4 A ug 1 99 8 LA - UR - 98 - 3390 Comment on “ Regge Trajectories for All Flavors ”

In a recent Letter [1] (and in ref. [2]), Filipponi, Pancheri and Srivastava report on the construction of a formula for linear Regge trajectories for all quark flavors: α j ¯ i (t) = 0.57 − (m i + m j) GeV + 0.9 GeV 2 1 + 0.2 (m i +m j GeV) 3/2 t, (1) where m i , m j are the corresponding constituent quark masses for the j ¯ i trajectory. As the authors of [1, 2] remark, no unique quark mass can be extracted from (1), and each trajectory α j ¯ i (t) rather corresponds to its own set (m i , m j). The values of m i can be extracted by using the vector meson masses with hidden flavor into Eq. (1): α i ¯ i (M 2 i ¯ i) = 1. Such an extraction gives (in GeV, n = u, d, and the superscript indicates the trajec-tory from which the corresponding value is extracted) m ρ n = 0.05, m φ s = 0.23, m J/ψ c = 1.70, m Υ b = 5.12. Then, the values of m i 's for the j ¯ i, i = j trajectories should be related to the above hidden-flavor values by additivity of trajectory intercepts. This additivity is satisfied in two-dimensional QCD and many QCD-motivated models ([3] and references therein), and therefore should be considered as a firmly established theoretical constraint on Regge trajectories. It is easily seen that in the case of the trajectories (1), this constraint implies m ρ n +m J/ψ c = m