Effective Lagrangian approach to the theory of [eta] photoproduction in the [ital N][sup *](1535) region

Journal Article · Sat Apr 01 04:00:00 EST 1995 · Physical Review, D (Particles Fields); (United States)

DOI:https://doi.org/10.1103/PhysRevD.51.3237· OSTI ID:6475015

Benmerrouche, M; Mukhopadhyay, N C ^[1]; Zhang, J F ^[2]

---

1. Physics Department, Rensselaer Polytechnic Institute, Troy, New York 12180-3590 (United States) Saskatchewan Accelerator Laboratory, University of Saskatchewan, Saskatoon, Sakatchewan, S7N 0W0 (Canada)
2. Physics Department, Rensselaer Polytechnic Institute, Troy, New York 12180-3590 (United States)

At the photon point, we determine it to be (2.2[plus minus]0.2)[times]10[sup [minus]1] GeV[sup [minus]1] from the old data base, and (2.2[plus minus]0.1)[times]10[sup [minus]1] GeV[sup [minus]1] from a combination of old data base and new Bates data. We obtain the helicity amplitude for [ital N][sup *](1535)[r arrow][gamma][ital p] to be [ital A][sub 1/2]=(97[plus minus]7)[times]10[sup [minus]3] GeV[sup [minus]1/2] from the old data base, and [ital A][sub 1/2]=(97[plus minus]6)[times]10[sup [minus]3] GeV[sup [minus]1/2] from the combination of the old data base and new Bates data, compared with the results of the analysis of pion photoproduction yielding 74[plus minus]11, in the same units. The observed differential cross section is not very sensitive to either the nature of the [eta]-nucleon coupling or to the precise value of the coupling constant; we extract a broad range of values for the [eta][ital NN] pseudoscalar coupling constant: 0.2[le][ital g][sub [eta]][le]6.2 from our analysis of all available data. We predict, in our ELA, the angular distributions for a critical series of experiments at Mainz, and find them to be in good agreement with the preliminary Mainz data. Finally, we discuss implications for future experimental studies with real photons at the Continuous Electron Beam Accelerator Facility (CEBAF) and other emerging medium-energy electron accelerators. Polarization observables, in particular, invite special scrutiny at high precision.

• OSTI ID: 6475015
• Journal Information: Physical Review, D (Particles Fields); (United States), Journal Name: Physical Review, D (Particles Fields); (United States) Vol. 51:7; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

662240 -- Models for Strong Interactions-- (1992-)
662330* -- Photon & Charged-Lepton Interactions with Hadrons-- (1992)
663300 -- Nuclear Reactions & Scattering
General-- (1992-)
663410 -- Photonuclear Reactions & Photon Scattering-- (1992-)
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
AMPLITUDES
ANGULAR DISTRIBUTION
BARYONS
BASIC INTERACTIONS
BOSONS
COUPLING CONSTANTS
CROSS SECTIONS
DIFFERENTIAL CROSS SECTIONS
DISTRIBUTION
ELECTROMAGNETIC INTERACTIONS
ELEMENTARY PARTICLES
ETA MESONS
FERMIONS
FUNCTIONS
HADRONS
HELICITY
INTERACTIONS
LAGRANGIAN FUNCTION
MESONS
N BARYONS
N-1535 BARYONS
PARTICLE INTERACTIONS
PARTICLE PRODUCTION
PARTICLE PROPERTIES
PHOTOPRODUCTION
PIONS
POLARIZATION
PSEUDOSCALAR MESONS
VECTOR MESONS