Measurements of the proton and deuteron spin structure functions g(1) and g(2)
Measurements of the proton and deuteron spin structure functions g(1) and g(2)
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DOI：
10.1103/physrevd.58.112003
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发表时间：
1998-02
影响因子：
5
通讯作者：
E143 collaboration
中科院分区：
文献类型：
--
作者：
E143 collaboration
测量质子和氘核自旋结构函数g1在束能量为29.1，16.2，和9.7 GeV和g2在束能量为29.1 GeV的报告。在固定的Q**2 = 3（GeV/c）**2下，使用完整的数据集计算了g1对x的积分。研究了比值g1/F1对Q**2的依赖性，发现当Q**2 > 1（GeV/c）**2时，Q**2很小。在实验精度范围内的g2数据很好地描述了Wandzura-Wilczek twist-2的贡献。提取Twist-3矩阵元素并与理论预测进行比较。测量的不对称性A2，发现是显着小于质子和氘核目标的阳性极限。质子的A2被发现是积极的和不一致的零。在共振区的g1的测量显示出强烈的变化与x和Q**2，从非极化数据提取的共振振幅一致。这些数据使我们能够研究的Q**2的依赖性的一阶矩的g1以下的缩放区域。
Measurements are reported of the proton and deuteron spin structure functions g1 at beam energies of 29.1, 16.2, and 9.7 GeV and g2 at a beam energy of 29.1 GeV. The integrals of g1 over x have been evaluated at fixed Q**2 = 3 (GeV/c)**2 using the full data set. The Q**2 dependence of the ratio g1/F1 was studied and found to be small for Q**2 > 1 (GeV/c)**2. Within experimental precision the g2 data are well-described by the Wandzura-Wilczek twist-2 contribution. Twist-3 matrix elements were extracted and compared to theoretical predictions. The asymmetry A2 was measured and found to be significantly smaller than the positivity limit for both proton and deuteron targets. A2 for the proton is found to be positive and inconsistent with zero. Measurements of g1 in the resonance region show strong variations with x and Q**2, consistent with resonant amplitudes extracted from unpolarized data. These data allow us to study the Q**2 dependence of the first moments of g1 below the scaling region.