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Title: The electromagnetic Sigma-to-Lambda hyperon transition form factors at low energies

Using dispersion theory the low-energy electromagnetic form factors for the transition of a Sigma to a Lambda hyperon are related to the pion vector form factor. The additionally required input, i.e. the two-pion-Sigma-Lambda amplitudes are determined from relativistic next-to-leading-order (NLO) baryon chiral perturbation theory including the baryons from the octet and optionally from the decuplet. Pion rescattering is again taken into account by dispersion theory. It turns out that the inclusion of decuplet baryons is not an option but a necessity to obtain reasonable results. The electric transition form factor remains very small in the whole low-energy region. The magnetic transition form factor depends strongly on one not very well determined low-energy constant of the NLO Lagrangian. Furthermore, one obtains reasonable predictive power if this low-energy constant is determined from a measurement of the magnetic transition radius. Such a measurement can be performed at the future Facility for Antiproton and Ion Research (FAIR).
Authors:
 [1] ;  [2] ;  [2]
  1. Uppsala Univ., Uppsala (Sweden); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
  2. Uppsala Univ., Uppsala (Sweden)
Publication Date:
Report Number(s):
JLAB-THY-17-2510; DOE/OR/23177-4186; arXiv:1701.09130
Journal ID: ISSN 1434-6001; PII: 860
Grant/Contract Number:
AC05-06OR23177
Type:
Accepted Manuscript
Journal Name:
European Physical Journal. A
Additional Journal Information:
Journal Volume: 53; Journal Issue: 6; Journal ID: ISSN 1434-6001
Publisher:
Springer
Research Org:
Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
OSTI Identifier:
1369457

Granados, Carlos, Leupold, Stefan, and Perotti, Elisabetta. The electromagnetic Sigma-to-Lambda hyperon transition form factors at low energies. United States: N. p., Web. doi:10.1140/epja/i2017-12324-4.
Granados, Carlos, Leupold, Stefan, & Perotti, Elisabetta. The electromagnetic Sigma-to-Lambda hyperon transition form factors at low energies. United States. doi:10.1140/epja/i2017-12324-4.
Granados, Carlos, Leupold, Stefan, and Perotti, Elisabetta. 2017. "The electromagnetic Sigma-to-Lambda hyperon transition form factors at low energies". United States. doi:10.1140/epja/i2017-12324-4. https://www.osti.gov/servlets/purl/1369457.
@article{osti_1369457,
title = {The electromagnetic Sigma-to-Lambda hyperon transition form factors at low energies},
author = {Granados, Carlos and Leupold, Stefan and Perotti, Elisabetta},
abstractNote = {Using dispersion theory the low-energy electromagnetic form factors for the transition of a Sigma to a Lambda hyperon are related to the pion vector form factor. The additionally required input, i.e. the two-pion-Sigma-Lambda amplitudes are determined from relativistic next-to-leading-order (NLO) baryon chiral perturbation theory including the baryons from the octet and optionally from the decuplet. Pion rescattering is again taken into account by dispersion theory. It turns out that the inclusion of decuplet baryons is not an option but a necessity to obtain reasonable results. The electric transition form factor remains very small in the whole low-energy region. The magnetic transition form factor depends strongly on one not very well determined low-energy constant of the NLO Lagrangian. Furthermore, one obtains reasonable predictive power if this low-energy constant is determined from a measurement of the magnetic transition radius. Such a measurement can be performed at the future Facility for Antiproton and Ion Research (FAIR).},
doi = {10.1140/epja/i2017-12324-4},
journal = {European Physical Journal. A},
number = 6,
volume = 53,
place = {United States},
year = {2017},
month = {6}
}