标题： 论核结构函数的$Q^2$依赖性 显示英文标题

标题： On the $Q^2$ dependence of nuclear structure functions

摘要： 最近的高统计量NMC数据关于锡到碳的结构函数比值似乎首次表明，存在显著的$Q^2$依赖性，尤其是在Bjorken的$x$、$x < 0.05$和$Q^2 > 1 GeV^2$的小值情况下。 纯主导扭曲、基于微扰QCD的预测，与自由核子数据一致，得出的比值相当平坦，几乎没有或没有$Q^2$依赖性。 鉴于这种看似矛盾的情况，我们重新审视这种微扰模型在该运动学区域中对核结构函数的适用性。 我们发现，在实验误差范围内，该模型与所有数据一致，无需引入额外的高扭曲贡献。 该模型正确地再现了碳结构函数的$Q^2$依赖性。 我们还仔细检查了相应自旋依赖结构函数的$Q^2$依赖性。 显示英文摘要

摘要： The recent high statistics NMC data on the Tin to Carbon structure function ratio seems to indicate, for the first time, a significant $Q^2$ dependence, especially at small values of Bjorken $x$, $x < 0.05$, and $Q^2 > 1 GeV^2$. Pure leading twist, perturbative QCD--based predictions, which are consistent with the free nucleon data, yield a fairly flat ratio with little or no $Q^2$ dependence. In view of this seeming contradiction, we re-examine the applicability of such a perturbative model to nuclear structure functions in such a kinematical regime. We find that the model is consistent with all data, within experimental errors, without any need for introducing additional higher twist contributions. The model correctly reproduces the $Q^2$ dependence of the Carbon structure function as well. We also critically examine the $Q^2$ dependence of the corresponding spin dependent structure functions.