First Measurement of Beam-Recoil Observables C_x and C_z in Hyperon Photoproduction

Authors

M. J. Amaryan, Old Dominion UniversityFollow
H. Bagdasaryan, Old Dominion University
H. Bektasoglu, Old Dominion University
S. Bültmann, Old Dominion UniversityFollow
S. L. Careccia, Old Dominion University
K. V. Dharmawardane, Old Dominion University
G. E. Dodge, Old Dominion UniversityFollow
T. A. Forest, Old Dominion University
N. Guler, Old Dominion University
C. E. Hyde-Wright, Old Dominion UniversityFollow
N. Kalantarians, Old Dominion University
A. Klein, Old Dominion University
S. E. Kuhn, Old Dominion UniversityFollow
J. Lachniet, Old Dominion University
M. R. Niroula, Old Dominion University
R. A. Niyazov, Old Dominion University
L. M. Qin, Old Dominion University
F. Sabatié, Old Dominion University
S. Tkachenko, Old Dominion University
L. B. Weinstein, Old Dominion UniversityFollow
J. Yun, Old Dominion University
et al.
CLAS Collaboration

Document Type

Article

Publication Date

2007

DOI

10.1103/PhysRevC.75.035205

Publication Title

Physical Review C

Volume

75

Issue

3

Pages

1-25

Abstract

Spin transfer from circularly polarized real photons to recoiling hyperons has been measured for the reactions ^→γ + p → K⁺ + ^→Λ and ^→γ+p → K⁺ + ^→Σ⁰. The data were obtained using the CEBAF Large Acceptance Spectrometer (CLAS) detector at the Jefferson Lab for center-of-mass energies W between 1.6 and 2.53 GeV, and for -0.85 < cos θ^c.m._K+ < +0.95. For the Λ, the polarization transfer coefficient along the photon momentum axis, C_z, was found to be near unity for a wide range of energy and kaon production angles. The associated transverse polarization coefficient C_x is smaller than C_z by a roughly constant difference of unity. Most significantly, the total Λ polarization vector, including the induced polarization P, has magnitude consistent with unity at all measured energies and production angles when the beam is fully polarized. For the Σ⁰ this simple phenomenology does not hold. All existing hadrodynamic models are in poor agreement with these results.

Comments

© 2007 American Physical Society

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Publisher's version available at: https://doi.org/10.1103/PhysRevC.75.035205

Original Publication Citation

Amaryan, M.J., Bültmann, S., Dodge, G.E., Hyde-Wright, C.E., Kuhn, S.E., Weinstein, L., et al., CLAS Collaboration (2007). First measurement of beam-recoil observables C_x and C_z in hyperon photoproduction. Physical Review C, 75(3), 1-25, Article 035205. https://doi.org/10.1103/PhysRevC.75.035205

ORCID

0000-0003-1582-2376 (Dodge), 0000-0001-7282-8120 (Hyde-Wright), 0000-0003-2243-6836 (Kuhn), 0000-0001-5416-2900 (Weinstein)

Repository Citation

Amaryan, M. J.; Bagdasaryan, H.; Bektasoglu, H.; Bültmann, S.; Careccia, S. L.; Dharmawardane, K. V.; Dodge, G. E.; Forest, T. A.; Guler, N.; Hyde-Wright, C. E.; Kalantarians, N.; Klein, A.; Kuhn, S. E.; Lachniet, J.; Niroula, M. R.; Niyazov, R. A.; Qin, L. M.; Sabatié, F.; Tkachenko, S.; Weinstein, L. B.; Yun, J.; et al.; and CLAS Collaboration, "First Measurement of Beam-Recoil Observables C_x and C_z in Hyperon Photoproduction" (2007). Physics Faculty Publications. 502.
https://digitalcommons.odu.edu/physics_fac_pubs/502