skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: First measurement of the polarization observable E in the p ( γ , π + ) n reaction up to 2.25 GeV

Journal Article · · Physics Letters B
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; « less

First results from the longitudinally polarized frozen-spin target (FROST) program are reported. The double-polarization observable E , for the reaction yp→π+n, has been measured using a circularly polarized tagged-photon beam, with energies from 0.35 to 2.37 GeV. The final-state pions were detected with the CEBAF Large Acceptance Spectrometer in Hall B at the Thomas Jefferson National Accelerator Facility. These polarization data agree fairly well with previous partial-wave analyses at low photon energies. Over much of the covered energy range, however, significant deviations are observed, particularly in the high-energy region where high-L multipoles contribute. The data have been included in new multipole analyses resulting in updated nucleon resonance parameters. Lastly, we report updated fits from the Bonn–Gatchina, Jülich–Bonn, and SAID groups.

Research Organization:
Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Jefferson Science Associates, LLC, Newport News, VA (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Nuclear Physics (NP)
Contributing Organization:
Jefferson Lab CLAS Collaboration; The CLAS Collaboration
Grant/Contract Number:
AC05-060R23177; SFB/TR16; AC05-06OR23177
OSTI ID:
1213897
Alternate ID(s):
OSTI ID: 1213680; OSTI ID: 1241245
Report Number(s):
JLAB-PHY-15-2025; DOE/OR/23177-3325; arXiv:1503.05163; S0370269315006541; PII: S0370269315006541
Journal Information:
Physics Letters B, Journal Name: Physics Letters B Vol. 750 Journal Issue: C; ISSN 0370-2693
Publisher:
ElsevierCopyright Statement
Country of Publication:
Netherlands
Language:
English
Citation Metrics:
Cited by: 25 works
Citation information provided by
Web of Science

Similar Records

Photon beam asymmetry Σ in the reaction γ p p ω for E= 1.152 to 1.876 GeV
Journal Article · Sun Oct 01 00:00:00 EDT 2017 · Physics Letters B · OSTI ID:1213897

Beam-target helicity asymmetry for γnπ-p in the N* resonance region
Journal Article · Fri Jun 16 00:00:00 EDT 2017 · Physical Review Letters · OSTI ID:1213897

Comprehensive amplitude analysis of γγπ+π-,π0π0 and K¯K below 1.5 GeV
Journal Article · Fri Aug 15 00:00:00 EDT 2014 · Physical Review. D, Particles, Fields, Gravitation and Cosmology · OSTI ID:1213897