title: Precision measurement of the neutron spin asymmetryA(n)(1) and spin-flavor decomposition in the valence quark region.
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.
authors.affiliation: Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: X
authors.initials: X
authors.lastname: Zheng
authors.forename: K
authors.initials: K
authors.lastname: Aniol
authors.forename: D S
authors.initials: DS
authors.lastname: Armstrong
authors.forename: T D
authors.initials: TD
authors.lastname: Averett
authors.forename: W
authors.initials: W
authors.lastname: Bertozzi
authors.forename: S
authors.initials: S
authors.lastname: Binet
authors.forename: E
authors.initials: E
authors.lastname: Burtin
authors.forename: E
authors.initials: E
authors.lastname: Busato
authors.forename: C
authors.initials: C
authors.lastname: Butuceanu
authors.forename: J
authors.initials: J
authors.lastname: Calarco
authors.forename: A
authors.initials: A
authors.lastname: Camsonne
authors.forename: G D
authors.initials: GD
authors.lastname: Cates
authors.forename: Z
authors.initials: Z
authors.lastname: Chai
authors.forename: J-P
authors.initials: JP
authors.lastname: Chen
authors.forename: Seonho
authors.initials: S
authors.lastname: Choi
authors.forename: E
authors.initials: E
authors.lastname: Chudakov
authors.forename: F
authors.initials: F
authors.lastname: Cusanno
authors.forename: R De
authors.initials: RD
authors.lastname: Leo
authors.forename: A
authors.initials: A
authors.lastname: Deur
authors.forename: S
authors.initials: S
authors.lastname: Dieterich
authors.forename: D
authors.initials: D
authors.lastname: Dutta
authors.forename: J M
authors.initials: JM
authors.lastname: Finn
authors.forename: S
authors.initials: S
authors.lastname: Frullani
authors.forename: H
authors.initials: H
authors.lastname: Gao
authors.forename: J
authors.initials: J
authors.lastname: Gao
authors.forename: F
authors.initials: F
authors.lastname: Garibaldi
authors.forename: S
authors.initials: S
authors.lastname: Gilad
authors.forename: R
authors.initials: R
authors.lastname: Gilman
authors.forename: J
authors.initials: J
authors.lastname: Gomez
authors.forename: J-O
authors.initials: JO
authors.lastname: Hansen
authors.forename: D W
authors.initials: DW
authors.lastname: Higinbotham
authors.forename: W
authors.initials: W
authors.lastname: Hinton
authors.forename: T
authors.initials: T
authors.lastname: Horn
authors.forename: C W
authors.initials: CW
authors.lastname: De Jager
authors.forename: X
authors.initials: X
authors.lastname: Jiang
authors.forename: L
authors.initials: L
authors.lastname: Kaufman
authors.forename: J
authors.initials: J
authors.lastname: Kelly
authors.forename: W
authors.initials: W
authors.lastname: Korsch
authors.forename: K
authors.initials: K
authors.lastname: Kramer
authors.forename: J
authors.initials: J
authors.lastname: LeRose
authors.forename: D
authors.initials: D
authors.lastname: Lhuillier
authors.forename: N
authors.initials: N
authors.lastname: Liyanage
authors.forename: D J
authors.initials: DJ
authors.lastname: Margaziotis
authors.forename: F
authors.initials: F
authors.lastname: Marie
authors.forename: P
authors.initials: P
authors.lastname: Markowitz
authors.forename: K
authors.initials: K
authors.lastname: McCormick
authors.forename: Z-E
authors.initials: ZE
authors.lastname: Meziani
authors.forename: R
authors.initials: R
authors.lastname: Michaels
authors.forename: B
authors.initials: B
authors.lastname: Moffit
authors.forename: S
authors.initials: S
authors.lastname: Nanda
authors.forename: D
authors.initials: D
authors.lastname: Neyret
authors.forename: S K
authors.initials: SK
authors.lastname: Phillips
authors.forename: A
authors.initials: A
authors.lastname: Powell
authors.forename: T
authors.initials: T
authors.lastname: Pussieux
authors.forename: B
authors.initials: B
authors.lastname: Reitz
authors.forename: J
authors.initials: J
authors.lastname: Roche
authors.forename: R
authors.initials: R
authors.lastname: Roche
authors.forename: M
authors.initials: M
authors.lastname: Roedelbronn
authors.forename: G
authors.initials: G
authors.lastname: Ron
authors.forename: M
authors.initials: M
authors.lastname: Rvachev
authors.forename: A
authors.initials: A
authors.lastname: Saha
authors.forename: N
authors.initials: N
authors.lastname: Savvinov
authors.forename: J
authors.initials: J
authors.lastname: Singh
authors.forename: S
authors.initials: S
authors.lastname: Sirca
authors.forename: K
authors.initials: K
authors.lastname: Slifer
authors.forename: P
authors.initials: P
authors.lastname: Solvignon
authors.forename: P
authors.initials: P
authors.lastname: Souder
authors.forename: D J
authors.initials: DJ
authors.lastname: Steiner
authors.forename: S
authors.initials: S
authors.lastname: Strauch
authors.forename: V
authors.initials: V
authors.lastname: Sulkosky
authors.forename: A
authors.initials: A
authors.lastname: Tobias
authors.forename: G
authors.initials: G
authors.lastname: Urciuoli
authors.forename: A
authors.initials: A
authors.lastname: Vacheret
authors.forename: B
authors.initials: B
authors.lastname: Wojtsekhowski
authors.forename: H
authors.initials: H
authors.lastname: Xiang
authors.forename: Y
authors.initials: Y
authors.lastname: Xiao
authors.forename: F
authors.initials: F
authors.lastname: Xiong
authors.forename: B
authors.initials: B
authors.lastname: Zhang
authors.forename: L
authors.initials: L
authors.lastname: Zhu
authors.forename: X
authors.initials: X
authors.lastname: Zhu
authors.forename: P A
authors.initials: PA
authors.lastname: Zołnierczuk