| 摘要: |
The dipion transitions Upsilon(2S,3S,4S) -> Upsilon(1S,2S)pi pi are systematically studied by considering the mechanisms of the hadronization of soft gluons, exchanging the bottomoniumlike Z(b) states, and the bottom-meson loops. The strong pion-pion final-state interaction, especially including the channel coupling to K (K) over bar in the S-wave, is taken into account in a model-independent way using the dispersion theory. Through fitting to the available experimental data, we extract values of the transition chromo-polarizabilities vertical bar alpha(Upsilon(ms)Upsilon(ns))vertical bar, which measure the chromoelectric couplings of the bottomonia with soft gluons. It is found that the Z(b) exchange has a slight impact on the extracted chromopolarizablity values, and the obtained vertical bar alpha(Upsilon(2s)Upsilon(1s))vertical bar considering the Z(b) exchange is (0.29 +/- 0.20) GeV-3. Our results could be useful in studying the interactions of bottomonium with light hadrons. |
