English

Differential cross sections and recoil polarizations for the reaction gamma p -> K+ Sigma0

Nuclear Experiment 2014-11-21 v2 High Energy Physics - Experiment

Abstract

High-statistics measurements of differential cross sections and recoil polarizations for the reaction γpK+Σ0\gamma p \rightarrow K^+ \Sigma^0 have been obtained using the CLAS detector at Jefferson Lab. We cover center-of-mass energies (s\sqrt{s}) from 1.69 to 2.84 GeV, with an extensive coverage in the K+K^+ production angle. Independent measurements were made using the K+pπK^{+}p\pi^{-}(γ\gamma) and K+pK^{+}p(π,γ\pi^-, \gamma) final-state topologies, and were found to exhibit good agreement. Our differential cross sections show good agreement with earlier CLAS, SAPHIR and LEPS results, while offering better statistical precision and a 300-MeV increase in s\sqrt{s} coverage. Above s2.5\sqrt{s} \approx 2.5 GeV, tt- and uu-channel Regge scaling behavior can be seen at forward- and backward-angles, respectively. Our recoil polarization (PΣP_\Sigma) measurements represent a substantial increase in kinematic coverage and enhanced precision over previous world data. At forward angles we find that PΣP_\Sigma is of the same magnitude but opposite sign as PΛP_\Lambda, in agreement with the static SU(6) quark model prediction of PΣPΛP_\Sigma \approx -P_\Lambda. This expectation is violated in some mid- and backward-angle kinematic regimes, where PΣP_\Sigma and PΛP_\Lambda are of similar magnitudes but also have the same signs. In conjunction with several other meson photoproduction results recently published by CLAS, the present data will help constrain the partial wave analyses being performed to search for missing baryon resonances.

Keywords

Cite

@article{arxiv.1006.0374,
  title  = {Differential cross sections and recoil polarizations for the reaction gamma p -> K+ Sigma0},
  author = {B. Dey and C. A. Meyer and M. Bellis and M. E. McCracken and M. Williams and the CLAS Collaboration},
  journal= {arXiv preprint arXiv:1006.0374},
  year   = {2014}
}

Comments

23 pages, 17 figures