Soft contribution to form factors of the γ*p→Δ+ transition

The purely nonperturbative soft contribution to the γ*p→Δ+ transition form factors is estimated using a model based on the local quark-hadron duality. In this approach, the soft contribution is shown to be dominated by the magnetic transition: the ratio GE*(Q2)/GM*(Q2) is small for all accessible Q2, in contrast with PQCD expectation that GE*(Q2)→-GM*(Q2). We also found that the soft contribution to the magnetic form factor is large enough to explain the magnitude of existing experimental data. copyright 1996 The American Physical Society