2010
DOI: 10.1016/j.physletb.2010.08.034
|View full text |Cite
|
Sign up to set email alerts
|

Quark helicity distributions from longitudinal spin asymmetries in muon–proton and muon–deuteron scattering

Abstract: Double-spin asymmetries for production of charged pions and kaons in semi-inclusive deep-inelastic muon scattering have been measured by the COMPASS experiment at CERN. The data, obtained by scattering a 160 GeV muon beam off a longitudinally polarised NH 3 target, cover a range of the Bjorken variable x between 0.004 and 0.7. A leading order evaluation of the helicity distributions for the three lightest quarks and antiquark flavours derived from these asymmetries and from our previous deuteron data is presen… Show more

Help me understand this report
View preprint versions

Search citation statements

Order By: Relevance

Paper Sections

Select...
1
1

Citation Types

9
82
0

Year Published

2010
2010
2018
2018

Publication Types

Select...
5
3
1

Relationship

1
8

Authors

Journals

citations
Cited by 133 publications
(91 citation statements)
references
References 44 publications
9
82
0
Order By: Relevance
“…We note that small strange-quark charges have also been observed in recent studies [15,16]. Within the present uncertainty, our results for the axial charges, g A and g s A , are consistent with the experimental values [17,18]. The suppression compared to the simple quark model estimate, g s A = 1 and g A = 5/3, was argued by one of the authors in Schwinger-Dyson analyses [19,20].…”
Section: Pos(lattice 2015)121supporting
confidence: 93%
“…We note that small strange-quark charges have also been observed in recent studies [15,16]. Within the present uncertainty, our results for the axial charges, g A and g s A , are consistent with the experimental values [17,18]. The suppression compared to the simple quark model estimate, g s A = 1 and g A = 5/3, was argued by one of the authors in Schwinger-Dyson analyses [19,20].…”
Section: Pos(lattice 2015)121supporting
confidence: 93%
“…In this case, there will be no strangeness contribution, Ás to ÁAE ¼ Áu þ Ád þ Ás þÁÁÁ, where, in our notation, Áq ¼ ÁAE q contains both the spin of the quarks q and of the antiquarks " q. Experimentally, Ás is obtained by integrating the strangeness contribution ÁsðxÞ to the spin structure function g 1 over the momentum fraction x. The integral over the range in which data exist agrees with zero; see, e.g., new COMPASS data [2,3] for x ! 0:004 or HERMES data [4] for x !…”
mentioning
confidence: 88%
“…This fact has surprised many physicists, and many theoretical studies trying to explain this "proton spin crisis" have been done [15,[17][18][19][20] with no definitive consensus between them. Currently the experimental studies continue [21], and the recent experimental data of the sum of the quark spin contribution to the nucleon spin is given by [22] ∆Σ = 0.32 ± 0.03 ± 0.03 .…”
Section: Introductionmentioning
confidence: 99%