标题： Roper共振的电产生和构成夸克模型 显示英文标题

标题： Electroproduction of the Roper resonance and the constituent quark model

摘要： 在光前组成夸克模型中进行了一次无参数的$N - P_{11}(1440)$电磁跃迁形式因子评估，在这次评估中首次使用了质量算符的本征函数，该质量算符在重子波函数中产生了大量的构型混合。 采用了一个单体电磁流，其中包含了从π介子和核子实验数据中分析得出的唯象组成夸克形式因子。 对于$Q^2$到几个$(GeV/c)^2$，与弹性通道中发现的增强不同，构型混合的效果导致相对于基于简单高斯型假设的相对论和非相对论计算，所计算的螺旋度振幅显著减小。 显示英文摘要

摘要： A parameter-free evaluation of the $N - P_{11}(1440)$ electromagnetic transition form factors is performed within a light-front constituent quark model, using for the first time the eigenfunctions of a mass operator which generates a large amount of configuration mixing in baryon wave functions. A one-body electromagnetic current, which includes the phenomenological constituent quark form factors already determined from an analysis of pion and nucleon experimental data, is adopted. For $Q^2$ up to few $(GeV/c)^2$, at variance with the enhancement found in the elastic channel, the effect of configuration mixing results in a significant suppression of the calculated helicity amplitudes with respect to both relativistic and non-relativistic calculations, based on a simple gaussian-like ansatz for the baryon wave functions.