RECORD
$Q^2$ Dependence of Quadrupole Strength in the $\gamma^*p\to\Delta^+(1232)\to p \pi^0$ Transition
High Energy Physics - Experiment · Submitted 3 Oct 2001
abstract compiled · 2026-09-23 · no language-model review
The authors' main claim Results are best described by recent unitary models in which the pion cloud plays a dominant role.
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
The abstract, sentence by sentence
Models of baryon structure predict a small quadrupole deformation of the nucleon due to residual tensor forces between quarks or distortions from the pion cloud. Sensitivity to quark versus pion degrees of freedom occurs through the $Q^2$ dependence of the magnetic ($M_{1+}$), electric ($E_{1+}$), and scalar ($S_{1+}$) multipoles in the $\gamma^* p \to \Delta^+ \to p \pi^0$ transition. We report new experimental values for the ratios $E_{1+}/M_{1+}$ and $S_{1+}/M_{1+}$ over the range $Q^2$= 0.4-1.8 GeV$^2$, extracted from precision $p(e,e 'p)\pi^{\circ}$ data using a truncated multipole expansion. Results are best described by recent unitary models in which the pion cloud plays a dominant role.
background contribution method result interpretation main claim
| # | sentence | role | the authors' own work | states the main conclusion | strength |
|---|---|---|---|---|---|
| s0 | Models of baryon structure predict a small quadrupole deformation of the nucleon due to residual tensor forces between quarks or distortions from the pion cloud. | background 1.00 | 0.03 | 0.03 | asserted 0.80 |
| s1 | Sensitivity to quark versus pion degrees of freedom occurs through the $Q^2$ dependence of the magnetic ($M_{1+}$), electric ($E_{1+}$), and scalar ($S_{1+}$) multipoles in the $\gamma^* p \to \Delta^+ \to p \pi^0$ transition. | background 0.98 | 0.05 | 0.05 | asserted 0.96 |
| s2 | We report new experimental values for the ratios $E_{1+}/M_{1+}$ and $S_{1+}/M_{1+}$ over the range $Q^2$= 0.4-1.8 GeV$^2$, extracted from precision $p(e,e 'p)\pi^{\circ}$ data using a truncated multipole expansion. | contribution 0.91 | 0.97 | 0.08 | asserted 1.00 |
| s3 | Results are best described by recent unitary models in which the pion cloud plays a dominant role. | interpretation 0.99 | 0.62 | 0.87 | asserted 0.91 |
What was examined, and what was not
- arXiv listing abstract v3
- full text
- figures and tables
- references and citing sentences
- relations to other papers
- P abstract
- S sections
- T body sentences
- C citations
- R cross-paper relations
The paper
Original abstract
Models of baryon structure predict a small quadrupole deformation of the nucleon due to residual tensor forces between quarks or distortions from the pion cloud. Sensitivity to quark versus pion degrees of freedom occurs through the $Q^2$ dependence of the magnetic ($M_{1+}$), electric ($E_{1+}$), and scalar ($S_{1+}$) multipoles in the $\gamma^* p \to \Delta^+ \to p \pi^0$ transition. We report new experimental values for the ratios $E_{1+}/M_{1+}$ and $S_{1+}/M_{1+}$ over the range $Q^2$= 0.4-1.8 GeV$^2$, extracted from precision $p(e,e 'p)\pi^{\circ}$ data using a truncated multipole expansion. Results are best described by recent unitary models in which the pion cloud plays a dominant role.
Human review
References
How the literature uses it
10 arXiv papers cite this in 14 sentences
Papers citing it · 9 sentences without a confident label
Uses its data or values 3 papers
-
In this plot, we have separated the data of CLAS (2002) [ref] , CLAS (2006) [ref] , CLAS (2009) [ref] , Hall C [ref] and Hall A [ref] from JLab as well as MAMI [ref] and Blomberg (2016) [ref] .
Impact of JLab data on the determination of GPDs at zero skewness and new insights from transition form factors $ N\rightarrow \Delta $ · Nucleon to $Δ$ electromagnetic transition · 0.88
-
Finally we use the following data for the $N →Δ$ transition: * The magnetic form factor normalized to the dipole form factor $G_M^*/(3 G_D)$ from [ref] . * The ratio of the electric quadrupole to the magnetic form factor $R_EM$ from [ref] . * The ratio of the Coulomb quadrupole to the magnetic form factor $R_SM$ from [ref] .
The Nucleon Distribution Amplitudes and their application to nucleon form factors and the $N \to \Delta$ transition at intermediate values of $Q^2$ · Results for the form factors at intermediate momentum transfer · 0.99
-
For the resonances $P_11(1440)$ and $S_11(1535)$, the values of $A_1/2$ at $Q^2=0$ are taken from the PDG [ref] , whereas the parameters $a_1$ and $b_1$ are obtained by fitting the meson electroproduction data on the cross section at various $Q^2$ as measured in the CLAS experiment [ref] .
Weak charged current induced electron and positron scattering off proton at JLab and MAMI energies · Weak vector form factors: · 0.91
Compares with it 1 paper
-
We note that the description of the structure functions does indeed agree with the results of Refs. [ref] in nearly all cases, apart from a discrepancy in $σ_LT$ at $W=1.14$ GeV.
J\"ulich-Bonn-Washington Model for Pion Electroproduction Multipoles · Fit results · 1.00
Discussion
Know something about this paper? Leave a comment, or highlight any passage above to comment on it.