摘要: |
The measured electromagnetic form factors of A hyperon in the timelike region are significantly deviated from pQCD prediction. We attribute the nonvanishing cross section near threshold to be the contribution of below-threshold phi(2170) state, supporting its exotic structure. Above the threshold, we find significant role of a wide vector meson with the mass of around 2.34 GeV, which would be the same state present in pp annihilation reactions. As a result, we give a satisfactory description of the behavior of existing data without modifying pQCD expectation. |