2004/06/17 by Achim Geiser, Geiser, Achim
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #hep-ex
paper · pdf · doi:10.48550/arxiv.hep-ex/0406046
To appear in the proceedings of 39th Rencontres de Moriond on QCD and High-Energy Hadronic Interactions, La Thuile, Italy, 28 Mar - 4 Apr 2004
arxiv created 2004/06/17 · arxiv updated 2019/08/13
Recent results on light hadron spectroscopy are reported, with special emphasis on the evidence for a narrow baryonic state decaying to Ks p and Ks pbar, compatible with the pentaquark state theta+ observed by fixed target experiments. The data were collected with the ZEUS detector at HERA using an integrated luminosity of 121 pb-1. The analyses were performed in the central rapidity region of inclusive deep inelastic scattering at an ep centre-of-mass energy of 300-318 GeV. Evidence for a narrow resonance in the Ks p and Ks pbar invariant mass spectrum is obtained, with mass 1521.5 ± 1.5(stat)+2.8-1.7(syst) and width consistent with the experimental resolution. If the Ks p part of the signal is identified with the strange pentaquark theta+, the Ks pbar part is the first evidence for its antiparticle, thetabar-. Supporting results on other light hadron resonances are also discussed.