论文部分内容阅读
The helicity amplitude A_(1/2)~P for the electromagnetic transition γ~*N→N~*(1535) is investigated. It is found that a new mechanism γ~*→ qq plays an important role in order to improve the description of this transition. On one hand, the A_(1/2)~P is decreased to fall in the data range at the photon point Q~2=0, while on the other hand, the new mechanism makes the function A_(1/2)~P(Q~2) to decrease more slowly vs increasing Q~2, as required by the data.