共振区域中的质子自旋结构。

Proton spin structure in the resonance region.

作者信息

Wesselmann F R, Slifer K, Tajima S, Aghalaryan A, Ahmidouch A, Asaturyan R, Bloch F, Boeglin W, Bosted P, Carasco C, Carlini R, Cha J, Chen J P, Christy M E, Cole L, Coman L, Crabb D, Danagoulian S, Day D, Dunne J, Elaasar M, Ent R, Fenker H, Frlez E, Gan L, Gaskell D, Gomez J, Hu B, Jones M K, Jourdan J, Keith C, Keppel C E, Khandaker M, Klein A, Kramer L, Liang Y, Lichtenstadt J, Lindgren R, Mack D, McKee P, McNulty D, Meekins D, Mkrtchyan H, Nasseripour R, Niculescu I, Normand K, Norum B, Pocanic D, Prok Y, Raue B, Reinhold J, Roche J, Rohe D, Rondón O A, Savvinov N, Sawatzky B, Seely M, Sick I, Smith C, Smith G, Stepanyan S, Tang L, Testa G, Vulcan W, Wang K, Warren G, Wood S, Yan C, Yuan L, Yun J, Zeier M, Zhu H

机构信息

University of Virginia, Charlottesville, VA 22903, USA.

出版信息

Phys Rev Lett. 2007 Mar 30;98(13):132003. doi: 10.1103/PhysRevLett.98.132003.

DOI:10.1103/PhysRevLett.98.132003

PMID:17501192

Abstract

We have examined the spin structure of the proton in the region of the nucleon resonances (1.085 GeV<W<1.910 GeV) at an average four momentum transfer of Q2=1.3 GeV2. Using the Jefferson Lab polarized electron beam, a spectrometer, and a polarized solid target, we measured the asymmetries A|| and A(perpendicular) to high precision, and extracted the asymmetries A1 and A2, and the spin structure functions g1 and g2. We found a notably nonzero A(perpendicular), significant contributions from higher-twist effects, and only weak support for polarized quark-hadron duality.

摘要

我们在平均四动量转移为Q2 = 1.3 GeV2的情况下，研究了核子共振区域（1.085 GeV < W < 1.910 GeV）内质子的自旋结构。利用杰斐逊实验室的极化电子束、一台光谱仪和一个极化固体靶，我们高精度地测量了纵向不对称性A||和横向不对称性A⊥，并提取了不对称性A1和A2以及自旋结构函数g1和g2。我们发现横向不对称性A⊥显著非零，高阶扭转效应有显著贡献，并且对极化夸克 - 强子对偶性仅有微弱支持。