|
|||||
|
|
Precision measurement of the neutron spin asymmetryA(n)(1) and spin-flavor decomposition in the valence quark region |
|
| Authors: | Zheng X Aniol K Armstrong D S Averett T D Bertozzi W Binet S Burtin E Busato E Butuceanu C Calarco J Camsonne A Cates G D Chai Z Chen J-P Choi Seonho Chudakov E Cusanno F Leo R De Deur A Dieterich S Dutta D Finn J M Frullani S Gao H Gao J Garibaldi F Gilad S Gilman R Gomez J Hansen J-O Higinbotham D W Hinton W Horn T De Jager C W Jiang X Kaufman L Kelly J Korsch W Kramer K LeRose J Lhuillier D Liyanage N Margaziotis D J Marie F Markowitz P McCormick K Meziani Z-E Michaels R Moffit B Nanda S Neyret D Phillips S K Powell A Pussieux T Reitz B Roche J Roche R Roedelbronn M Ron G Rvachev M Saha A |
| Institution: | Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA. |
| Abstract: | We have measured the neutron spin asymmetry A(n)(1) with high precision at three kinematics in the deep inelastic region at x=0.33, 0.47, and 0.60, and Q(2)=2.7, 3.5, and 4.8 (GeV/c)(2), respectively. Our results unambiguously show, for the first time, that A(n)(1) crosses zero around x=0.47 and becomes significantly positive at x=0.60. Combined with the world proton data, polarized quark distributions were extracted. Our results, in general, agree with relativistic constituent quark models and with perturbative quantum chromodynamics (PQCD) analyses based on the earlier data. However they deviate from PQCD predictions based on hadron helicity conservation. |
| Keywords: | |
| 本文献已被 PubMed 等数据库收录！ | |