I. Hleiqawi

K^*0 Photoproduction off the proton at CLAS

We report here differential cross sections for the reaction {gamma}p {yields} K*{sup 0}{Sigma}{sup +} for the first time with high statistics. The measurements were done using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. Data were taken at 3.115 GeV electron beam energy using tagged photons incident upon a liquid hydrogen target. In addition, our analysis provides information about nucleon resonances and their couplings to K* decay. Our data will be used to test predictions of theoretical models of K* production, and to provide constraints on the K*{Sigma}N coupling constant used in these models.

Cross sections for the {gamma}p{yields}K*{sup 0}{sigma}{sup +} reaction at E{sub {gamma}}=1.7-3.0 GeV

Differential cross sections for the reaction {gamma}p{yields}K*{sup 0}{sigma}{sup +} are presented in the photon energy range of 1.7 to 3.0 GeV. The K*{sup 0} was detected by its decay products, K{sup +}{pi}{sup -}, in the Continuous Electron Beam Accelerator Facilitys large acceptance spectrometer (CLAS) detector at the Thomas Jefferson National Accelerator Facility. These data are the first K*{sup 0} photoproduction cross sections ever published over a broad range of angles. Comparison with a theoretical model based on the vector and tensor K*-quark couplings shows good agreement with the data, except at forward angles, suggesting that the role of scalar {kappa} meson exchange should be investigated.Differential cross sections for the reaction γp→K*0Σ+ are presented in the photon energy range of 1.7 to 3.0 GeV. The K*0 was detected by its decay products, K+π−, in the Continuous Electron Beam Accelerator Facilitys large acceptance spectrometer (CLAS) detector at the Thomas Jefferson National Accelerator Facility. These data are the first K*0 photoproduction cross sections ever published over a broad range of angles. Comparison with a theoretical model based on the vector and tensor K∗-quark couplings shows good agreement with the data, except at forward angles, suggesting that the role of scalar κ meson exchange should be investigated.

Search for the {theta}{sup +} Pentaquark in the Reaction {gamma}d{yields}pK{sup -}K{sup +}n

A search for the Theta+ in the reaction gammad --> pK-K+n was completed using the CLAS detector at Jefferson Lab. A study of the same reaction, published earlier, reported the observation of a narrow Theta+ resonance. The present experiment, with more than 30 times the integrated luminosity of our earlier measurement, does not show any evidence for a narrow pentaquark resonance. The angle-integrated upper limit on Theta+ production in the mass range of 1.52-1.56 GeV/c2 for the gammad --> pK-Theta+ reaction is 0.3 nb (95% C.L.). This upper limit depends on assumptions made for the mass and angular distribution of Theta+ production. Using Lambda(1520) production as an empirical measure of rescattering in the deuteron, the cross section upper limit for the elementary gamman --> K-Theta+ reaction is estimated to be a factor of 10 higher, i.e., approximately 3 nb (95% C.L.).

Electroproduction of K∗0 mesons at CLAS

Abstract The electroproduction of K ∗ 0 mesons using the CLAS detector is described. Data for two electron beam energies, 4.056 and 4.247 GeV, were measured and the normalized yields are compared.