标题： 二维可积渐近自由模型的结构函数 显示英文标题

标题： Structure functions of 2d integrable asymptotically free models

摘要： 我们利用非微扰的S-矩阵bootstrap程序，研究了二维（渐近自由）非线性O$(n) \sigma$-模型中的结构函数。 特别是{\it 展现出精确的小（Bjorken）$x$行为}；该结构相当普遍，可能在一大类（可积）渐近自由模型中相同。 四维QCD中小$x$行为的结构函数也可能满足类似的普适公式。 在$n=3$模型的特殊情况下，对于$-q^2/M^2<10^5$的整个$x$范围，准确计算了结构函数，并且一些矩与重整化微扰理论的结果进行了比较。 还对$1/n$近似下的结构函数作了一些评述。 显示英文摘要

摘要： We investigate structure functions in the 2--dimensional (asymptotically free) non--linear O$(n) \sigma$--models using the non--perturbative S--matrix bootstrap program. In particular the {\it exact small (Bjorken) $x$ behavior is exhibited}; the structure is rather universal and is probably the same in a wide class of (integrable) asymptotically free models. Structurally similar universal formulae may also hold for the small $x$ behavior of QCD in 4--dimensions. Structure functions in the special case of the $n=3$ model are accurately computed over the whole $x$ range for $-q^2/M^2<10^5$, and some moments are compared with results from renormalized perturbation theory. Some remarks concerning the structure functions in the $1/n$ approximation are also made.