Transverse charge and current densities in the nucleon from dispersively improved chiral effective field theory
Identifiers
Permanent link (URI): http://hdl.handle.net/10017/60625DOI: 10.1103/PhysRevD.106.054005
ISSN: 0556-2821
Publisher
American Physical Society
Date
2022-09-07Funders
Agencia Estatal de Investigación
Bibliographic citation
Alarcón Soriano, J.M. & Weiss, C. 2022, "Transverse charge and current densities in the nucleon from dispersively improved chiral effective field theory", Physical Review D: Particles and fields, vol. 106, art. no. 054005, pp. 1-21.
Project
info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PID2019-106080GB-C21/ES/FISICA HADRONICA Y CROMODINAMICA CUANTICA: DESDE LAS BAJAS ENERGIAS HASTA EL LHC/
Document type
info:eu-repo/semantics/article
Version
info:eu-repo/semantics/publishedVersion
Publisher's version
https://doi.org/10.1103/PhysRevD.106.054005Rights
Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)
Access rights
info:eu-repo/semantics/openAccess
Abstract
The transverse densities ρ1;2ðbÞ describe the distributions of electric charge and magnetic
moment at fixed light-front time and connect the nucleon’s elastic form factors with its partonic structure.
The dispersive representation of the form factors F1;2ðtÞ expresses the densities in terms of exchanges of
hadronic states in the t-channel and permits their analysis using hadronic physics methods. Purpose:
Compute the densities at peripheral distances b ¼ OðM−1
π Þ, where they are generated predominantly by the
two-pion states in the dispersive representation. Quantify the uncertainties. Methods: Dispersively
improved chiral effective field theory (DIχEFT) is used to calculate the isovector spectral functions
ImF1;2ðtÞ on the two-pion cut. The method includes ππ interactions (ρ resonance) through elastic unitarity
and provides realistic spectral functions up to t ≈ 1 GeV2. Higher-mass states are parametrized by effective
poles and constrained by sum rules (charges, radii, superconvergence relations). The densities ρ1;2ðbÞ are
obtained from their dispersive representation. Uncertainties are quantified by varying the spectral functions.
The method respects analyticity and ensures the correct b → ∞ asymptotic behavior of the densities.
Results: Accurate densities are obtained at all distances b ≳ 0.5 fm, with correct behavior down to b → 0.
The region of distances is quantified where transverse nucleon structure is governed by the two-pion state.
The light-front current distributions in the polarized nucleon are computed and discussed. Conclusions:
Peripheral nucleon structure can be computed from first principles using DIχEFT. The method can be
extended to generalized parton distributions and other nucleon form factors.
Files in this item
Files | Size | Format |
|
---|---|---|---|
Transverse_Alarcon_Phys_Rev_D_ ... | 1.085Mb |
|
Files | Size | Format |
|
---|---|---|---|
Transverse_Alarcon_Phys_Rev_D_ ... | 1.085Mb |
|
Collections
- FISICA - Artículos [76]