Differential cross sections and spin density matrix elements for the reaction gamma p -> p omega

High-statistics differential cross sections and spin density matrix elements for the reaction gamma p -> p omega have been measured using the CLAS at Jefferson Lab for center-of-mass (CM) energies from threshold up to 2.84 GeV. Results are reported in 112 10-MeV wide CM energy bins, each subdivided into cos(theta_CM) bins of width 0.1. These are the most precise and extensive omega photoproduction measurements to date. A number of prominent structures are clearly present in the data. Many of these have not previously been observed due to limited statistics in earlier measurements

The extraction of ϕ−N\phi-N total cross section from d(γ,pK+K−)nd(\gamma,pK^{+}K^{-})n

We report on the first measurement of the differential cross section of $\phi$-meson photoproduction for the $d(\gamma,pK^{+}K^{-})n$ exclusive reaction channel. The experiment was performed using a \textcolor{black}{tagged-photon} beam and the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. A combined analysis using data from the $d(\gamma,pK^{+}K^{-})n$ channel and those from a previous publication on coherent $\phi$ production on the deuteron has been carried out to extract the $\phi-N$ total cross section, $\sigma_{\phi N}$. The extracted $\phi-N$ total cross section favors a value above 20 mb. This value is larger than the value extracted using vector-meson dominance models for $\phi$ photoproduction on the proton.Comment: 7 pages 4 figure

Partial wave analysis of the reaction gamma p ---> p omega and the search for nucleon resonances

An event-based partial wave analysis (PWA) of the reaction gamma p -> p omega has been performed on a high-statistics dataset obtained using the CLAS at Jefferson Lab for center-of-mass energies from threshold up to 2.4 GeV. This analysis benefits from access to the world's first high-precision spin-density matrix element measurements, available to the event-based PWA through the decay distribution of omega ->pi(+)pi(-)pi(0). The data confirm the dominance of the t-channel pi(0) exchange amplitude in the forward direction. The dominant resonance contributions are consistent with the previously identified states F(15)(1680) and D(13)(1700) near threshold, as well as the G(17)(2190) at higher energies. Suggestive evidence for the presence of a J(P)=5/2(+) state around 2 GeV, a "missing" state, has also been found. Evidence for other states is inconclusive

Differential cross sections for the reactions γp→pη and γp→pη′

High-statistics differential cross sections for the reactions γp→pη and γp→pη′ have been measured using the CEBAF large acceptance spectrometer (CLAS) at Jefferson Lab for center-of-mass energies from near threshold up to 2.84 GeV. The η′ results are the most precise to date and provide the largest energy and angular coverage. The η measurements extend the energy range of the world’s large-angle results by approximately 300 MeV. These new data, in particular the η′ measurements, are likely to help constrain the analyses being performed to search for new baryon resonance states

Differential cross sections for the reactions gamma p ---> p eta and gamma p ---> p eta-prime

High-statistics differential cross sections for the reactions gamma p -> p eta and gamma p -> p eta' have been measured using the CEBAF large acceptance spectrometer (CLAS) at Jefferson Lab for center-of-mass energies from near threshold up to 2.84 GeV. The eta' results are the most precise to date and provide the largest energy and angular coverage. The. measurements extend the energy range of the world's large-angle results by approximately 300 MeV. These new data, in particular the eta' measurements, are likely to help constrain the analyses being performed to search for new baryon resonance states