Abstract
It is shown that two physical phenomena are important for high excitations: (i) the screening of the universal gluon-exchange potential and (ii) the flattening of the confining potential owing to creation of quark loops, and both effects are determined quantitatively. Taking the first effect into account, we predict the masses of the ground states with , 1, 2 in agreement with experiment. The flattening effect ensures the observed linear behavior of the radial Regge trajectories , where the slope is very sensitive to the parameter , which determines the weakening of the string tension at large distances. For the trajectory the linear behavior starts with and the values for and for are obtained. For the excited states the leptonic widths , , , , and are calculated, if these states are considered as purely states. The width increases if is mixed with the state, giving for a mixing angle almost equal widths: and .
- Received 18 March 2016
DOI:https://doi.org/10.1103/PhysRevD.93.074034
© 2016 American Physical Society