Observation of the pη^{'} Cusp in the New Precise Beam Asymmetry Σ Data for γp→pη.
Journal
Physical review letters
ISSN: 1079-7114
Titre abrégé: Phys Rev Lett
Pays: United States
ID NLM: 0401141
Informations de publication
Date de publication:
09 Oct 2020
09 Oct 2020
Historique:
received:
01
06
2020
revised:
24
07
2020
accepted:
28
08
2020
entrez:
23
10
2020
pubmed:
24
10
2020
medline:
24
10
2020
Statut:
ppublish
Résumé
Data on the beam asymmetry Σ in the photoproduction of η mesons off protons are reported for tagged photon energies from 1130 to 1790 MeV (mass range from W=1748 MeV to W=2045 MeV). The data cover the full solid angle that allows for a precise moment analysis. For the first time, a strong cusp effect in a polarization observable has been observed that is an effect of a branch-point singularity at the pη^{'} threshold [E_{γ}=1447 MeV (W=1896 MeV)]. The latest BnGa partial wave analysis includes the new beam asymmetry data and yields a strong indication for the N(1895)1/2^{-} nucleon resonance, demonstrating the importance of including all singularities for a correct determination of partial waves and resonance parameters.
Identifiants
pubmed: 33095637
doi: 10.1103/PhysRevLett.125.152002
doi:
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM