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Publication Title

Physical Review C






055208 (1-31)


High-statistics measurements of differential cross sections and spin density matrix elements for the reaction ᵞp → ϕp have been made using the CLAS detector at Jefferson Lab. We cover center-of-mass energies (√s) from 1.97 to 2.84 GeV, with an extensive coverage in the ϕ production angle. The high statistics of the data sample made it necessary to carefully account for the interplay between the ϕ natural lineshape and effects of the detector resolution, that are found to be comparable in magnitude. We study both the charged-(ϕ → K+ K-) and neutral( ϕ → (KOSKOL) K K- decay modes of the ϕ. Further, for the charged mode, we differentiate between the cases where the final K-is directly detected or its momentum reconstructed as the total missing momentum in the event. The two charged-mode topologies and the neutral-mode have different resolutions and are calibrated against each other. Extensive usage is made of kinematic fitting to improve the reconstructed ϕ mass resolution. Our final results are reported in 10- and mostly 30-MeV-wide √s bins for the charged-and the neutral-modes, respectively. Possible effects from K+Λ* channels with p K K- final states are discussed. These present results constitute the most precise and extensive ϕ photoproduction measurements to date and in conjunction with the ω photoproduction results recently published by CLAS, will greatly improve our understanding of low energy vector meson photoproduction.


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Original Publication Citation

Dey, B., Meyer, C. A., Bellis, M., Williams, M., Adhikari, K. P., Adikaram, D., . . . Collaboration, C. (2014). Data Analysis Techniques, Differential Cross Sections, and Spin Density Matrix Elements for the Reaction ᵞp → ϕp. Physical Review C, 89(5), 055208. doi:10.1103/PhysRevC.89.055208

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