skip to main content

DOE PAGESDOE PAGES

Title: Elastic and transition form factors of the Δ(1232)

Predictions obtained with a confining, symmetry-preserving treatment of a vector Ⓧ vector contact interaction at leading-order in a widely used truncation of QCD’s Dyson–Schwinger equations are presented for Δ and Ω baryon elastic form factors and the γN → Δ transition form factors. This simple framework produces results that are practically indistinguishable from the best otherwise available, an outcome which highlights that the key to describing many features of baryons and unifying them with the properties of mesons is a veracious expression of dynamical chiral symmetry breaking in the hadron bound-state problem. The following specific results are of particular interest. The Δ elastic form factors are very sensitive to m Δ. Hence, given that the parameters which define extant simulations of lattice-regularised QCD produce Δ-resonance masses that are very large, the form factors obtained therewith are a poor guide to properties of the Δ(1232). Considering the Δ-baryon’s quadrupole moment, whilst all computations produce a negative value, the conflict between theoretical predictions entails that it is currently impossible to reach a sound conclusion on the nature of the Δ-baryon’s deformation in the infinite momentum frame. Furthermore, results for analogous properties of the Ω baryon are less contentious. In connection with themore » N → Δ transition, the Ash-convention magnetic transition form factor falls faster than the neutron’s magnetic form factor and nonzero values for the associated quadrupole ratios reveal the impact of quark orbital angular momentum within the nucleon and Δ; and, furthermore, these quadrupole ratios do slowly approach their anticipated asymptotic limits.« less
Authors:
 [1] ;  [2] ;  [1] ;  [1] ;  [3] ;  [2]
  1. Argonne National Lab. (ANL), Argonne, IL (United States)
  2. Univ. of Science and Technology of China, Hefei (People's Republic of China)
  3. Forschungszentrum Julich and JARA, Julich (Germany)
Publication Date:
Grant/Contract Number:
AC02-06CH11357
Type:
Accepted Manuscript
Journal Name:
Few-Body Systems
Additional Journal Information:
Journal Volume: 55; Journal Issue: 1; Journal ID: ISSN 0177-7963
Publisher:
Springer
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
OSTI Identifier:
1368047

Segovia, Jorge, Chen, Chen, Cloet, Ian C., Roberts, Craig D., Schmidt, Sebastian M., and Wan, Shaolong. Elastic and transition form factors of the Δ(1232). United States: N. p., Web. doi:10.1007/s00601-013-0734-x.
Segovia, Jorge, Chen, Chen, Cloet, Ian C., Roberts, Craig D., Schmidt, Sebastian M., & Wan, Shaolong. Elastic and transition form factors of the Δ(1232). United States. doi:10.1007/s00601-013-0734-x.
Segovia, Jorge, Chen, Chen, Cloet, Ian C., Roberts, Craig D., Schmidt, Sebastian M., and Wan, Shaolong. 2013. "Elastic and transition form factors of the Δ(1232)". United States. doi:10.1007/s00601-013-0734-x. https://www.osti.gov/servlets/purl/1368047.
@article{osti_1368047,
title = {Elastic and transition form factors of the Δ(1232)},
author = {Segovia, Jorge and Chen, Chen and Cloet, Ian C. and Roberts, Craig D. and Schmidt, Sebastian M. and Wan, Shaolong},
abstractNote = {Predictions obtained with a confining, symmetry-preserving treatment of a vector Ⓧ vector contact interaction at leading-order in a widely used truncation of QCD’s Dyson–Schwinger equations are presented for Δ and Ω baryon elastic form factors and the γN → Δ transition form factors. This simple framework produces results that are practically indistinguishable from the best otherwise available, an outcome which highlights that the key to describing many features of baryons and unifying them with the properties of mesons is a veracious expression of dynamical chiral symmetry breaking in the hadron bound-state problem. The following specific results are of particular interest. The Δ elastic form factors are very sensitive to mΔ. Hence, given that the parameters which define extant simulations of lattice-regularised QCD produce Δ-resonance masses that are very large, the form factors obtained therewith are a poor guide to properties of the Δ(1232). Considering the Δ-baryon’s quadrupole moment, whilst all computations produce a negative value, the conflict between theoretical predictions entails that it is currently impossible to reach a sound conclusion on the nature of the Δ-baryon’s deformation in the infinite momentum frame. Furthermore, results for analogous properties of the Ω baryon are less contentious. In connection with the N → Δ transition, the Ash-convention magnetic transition form factor falls faster than the neutron’s magnetic form factor and nonzero values for the associated quadrupole ratios reveal the impact of quark orbital angular momentum within the nucleon and Δ; and, furthermore, these quadrupole ratios do slowly approach their anticipated asymptotic limits.},
doi = {10.1007/s00601-013-0734-x},
journal = {Few-Body Systems},
number = 1,
volume = 55,
place = {United States},
year = {2013},
month = {12}
}