Universal description of radially excited heavy and light vector mesons

A new qualitative stringlike picture for mesons is proposed which leads to a simple and intuitively clear generalization of linear radial Regge trajectories to the case of massive quarks. The obtained universal relation is successfully tested in the sector of unflavored vector mesons, where many radial excitations are known. Some new predictions are given. Our results suggest that the quark masses can be easily estimated from the spectra of radially excited mesons.

Figure 1

(a) A presumable spectrum of $S$-wave $\psi$ mesons. The experimental points are taken from Table 1. The circles stay for $\psi (4361)$ and $\psi (4634)$ observed recently by Belle Collaboration [20, 21]. (b) The spectrum of $S$-wave $\mathrm{\Upsilon }$ mesons.

Figure 2

(a) The spectrum (8) for the Fit A. (b) The spectrum (8) for the Fit B.