Precision Measurement of the Neutron Spin Asymmetry $A_1^n$ and Spin-Flavor Decomposition in the Valence Quark Region

et al. (The Jefferson Lab Hall A Collaboration); X. Zheng

RECORD

Precision Measurement of the Neutron Spin Asymmetry $A_1^n$ and Spin-Flavor Decomposition in the Valence Quark Region

X. Zheng, et al. (the Jefferson Lab Hall A Collaboration)

Nuclear Experiment · Submitted 13 Aug 2003

abstract compiled · 2026-09-23 · no language-model review

The authors' main claim Our results unambiguously show, for the first time, that $A_1^n$ crosses zero around $x=0.47$ and becomes significantly positive at $x=0.60$.

how it is stated · asserted 1.00 read the record →

Comment (0) Read on arXiv ↗

Cite ▾

arXiv IDnucl-ex/0308011 (version 3)

Pith IDFJ6O5HPE, Pith's permanent record of this paper and its review

Citationet al. (The Jefferson Lab Hall A Collaboration), X. Zheng. "Precision Measurement of the Neutron Spin Asymmetry $A_1^n$ and Spin-Flavor Decomposition in the Valence Quark Region." arXiv:nucl-ex/0308011 (2003). https://pith.science/paper/FJ6O5HPE

Claim paper

The compiled record

The paper's own sentences, arranged. Each label is drawn from a closed vocabulary; the number beside it is the probability the classifier gave that label. Numbers in the tables are the authors', checked by code. No sentence in this record was written by a model.

Open the compiled record

Compiled by classifier-1.13.0 via TypeSafe API, question bank abstract-p1-20260923, 2026-09-23: 1 request, 4,421 input tokens.

What the abstract itself states, as probabilities: claims first 0.83 · states limitation 0.45 · human participants 0.03 · controlled comparison 0.07 · randomized assignment 0.01 · states quantitative result 0.90 · compares with prior results 0.97 · mentions code or data availability 0.02.

The abstract, sentence by sentence

arXiv listing abstract v3. Results and the main claim are underlined; show every role.

We have measured the neutron spin asymmetry $A_1^n$ 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 $A_1^n$ 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.

background contribution method result interpretation main claim

What the classifier reports for each sentence. The number is the probability it gave the label.
#	sentence	role	the authors' own work	states the main conclusion	strength
s0	We have measured the neutron spin asymmetry $A_1^n$ 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.	contribution 0.72	0.98	0.05	asserted 1.00
s1	Our results unambiguously show, for the first time, that $A_1^n$ crosses zero around $x=0.47$ and becomes significantly positive at $x=0.60$.	result 1.00	0.96	0.82	asserted 1.00
s2	Combined with the world proton data, polarized quark distributions were extracted.	result 0.44	0.86	0.08	asserted 0.98
s3	Our results, in general, agree with relativistic constituent quark models and with perturbative quantum chromodynamics (pQCD) analyses based on the earlier data.	interpretation 0.87	0.73	0.09	asserted 0.66
s4	However they deviate from pQCD predictions based on hadron helicity conservation.	interpretation 0.51	0.78	0.15	asserted 1.00

What kind of paper the classifier reports this is: empirical study 1.00 · evidence from observation or experiment 1.00.

What was examined, and what was not

sources read

arXiv listing abstract v3

not examined

full text
figures and tables
references and citing sentences
relations to other papers

levels run

P abstract

not run

S sections
T body sentences
C citations
R cross-paper relations

Every quoted sentence on this record is the authors'. Every label is from Pith's closed vocabulary, with the probability shown beside it. Every number in the measurements table is the authors', checked by code. Record as JSON

The paper

Original abstract

We have measured the neutron spin asymmetry $A_1^n$ 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 $A_1^n$ 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.

Human review

How Pith checks papers → · Full audit of this paper →

References

Forward citations

Cited by 2 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

Exotica
hep-ph 2004-09 conditional novelty 5.0 of 10

Diquark correlations, not free quarks, organize hadron spectroscopy: they explain why exotic multiquark states are almost absent and predict that any pentaquarks sit in a positive-parity antidecuplet.
Parton Distribution Functions and their Generalizations
hep-ph 2025-07 unverdicted novelty 1.0 of 10

A textbook-style introduction to the definitions, QCD properties, experimental access, and current phenomenological status of PDFs and their generalizations.

How the literature uses it

5 arXiv papers cite this in 7 sentences

Each citing sentence is taken from the citing paper's LaTeX source and typed by Pith's classifier. A label appears at probability 0.8 or more (0.95 for support), a contest at 0.7 or more; the quoted words are the citing authors'. How each label was checked · JSON

Papers whose main result relates to this one's

Found among the papers closest to this one by title and main claim. Pith's classifier compared each pair's main results and a second model family confirmed the relation; checked against two further families, shown conflicts agreed 118 times in 120 and shown same results 218 times in 239. The quoted sentence is the other paper's main claim.

States the same result 1 paper

The results show for the first time that $A_1^n$ becomes positive at large $x$, strongly breaking SU(6) (spin-flavor) symmetry.

Neutron Spin Structure Measurements in JLab Hall A · 0.96

Papers citing it · 2 sentences without a confident label

Uses its data or values 1 paper

The JLab 6 GeV results [ref] showed that the ratio of the polarized to unpolarized PDF for the down quark, $Δd/d$ is negative up to $x=0.61$.

The Present and Future of QCD · One-dimensional Momentum Distributions of the Nucleon · 0.81

Compares with it 1 paper

Before closing, in order to deeply test the validity of the present approach, we compare in Fig. [ref] the calculation of $x^2 g_1^3(x)$ and $x^2 g_2^3(x)$ using Eq. ([ref]) with data [ref] .

$^3$He spin-dependent structure functions within the relativistic Light-Front Hamiltonian dynamics · S2: Explicit expression of the $^3$He SSFs · 0.86

Cites it as background 2 papers

The new century brought additional high-precision experiments at Jefferson Lab (Halls A [ref] , B [ref] and C [ref] ).

Detailed Study of Quark-Hadron Duality in Spin Structure Functions of the Proton and Neutron · Theoretical background · 0.94
Subsequent experiments with increasing precision and kinematic reach were performed at SLAC [ref] , HERMES [ref] , SMC [ref] , COMPASS [ref] , Jefferson Lab [ref] , and RHIC [ref] , and various global QCD analyses of these data in terms of spin-dependent parton distribution functions (PDFs) have been carried out [ref] .

Helicity-dependent distribution of strange quarks in the proton from nonlocal chiral effective theory · Introduction · 0.98

Discussion

Know something about this paper? Leave a comment, or highlight any passage above to comment on it.