Spin-dependent effects in the roughened string model for heavy quarkonia

Abstract

Using the recently proposed roughened string potential for heavy quarkonium, we calculate the spin splitting in the Jψ and γsystems. We show how the departure from linearity of this potential affects the hyperfine splitting in the P levels of these systems, in a way consistent with experimental data. This lends support to the recent observations that the confining part of the interquark potential is weaker than linear. © 1993 The American Physical Society.