Photoproduction of ∑[sup +]K[sub s]0] with the CBELSA∕TAPS-setup

Abstract

Albeit quark models explain the known baryon spectrum reasonably well, they all overpredict the number of states significantly. This is often called the “missing resonance” problem. It is speculated, that some of these resonances remained undetected in pi‐induced reactions, but have a sizeable coupling to channels with strangeness involved. This provided our motivation to measure cross sections and polarisation observables in associated Kaon‐Hyperon photoproduction with the focus on the ∑+Ks0 channel. Up to now, for this particular channel only limited data exists from the SAPHIR‐, CLAS‐ and CBELSA/TAPS‐collaboration for total and differential cross sections, and for recoil polarisation. Using the linearly polarised, energy tagged photon beam at the ELSA particle accelerator of Bonn University, data were taken with the combined photon spectrometers Crystal Barrel and TAPS. This setup is well suited to detect multi photon final states and therefore ideal to measure the reaction channel γp→∑+Ks0→pπ0π0π0→p6γ. Here the extraction of cross sections, the recoil polarisation P and the photon asymmetry ∑, which is measured for the first time, will be discussed.