Latest documents http://publikationen.stub.uni-frankfurt.de/index/index/ Fri, 14 Oct 2005 17:29:24 +0200 Fri, 14 Oct 2005 17:29:24 +0200 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/3488 Results of resonance searches in the Xi - pi -, Xi - pi +, Xi -bar+ pi -, and Xi -bar+ pi + invariant mass spectra in proton-proton collisions at sqrt[s]=17.2 GeV are presented. Evidence is shown for the existence of a narrow Xi - pi - baryon resonance with mass of 1.862±0.002 GeV/c2 and width below the detector resolution of about 0.018 GeV/c2. The significance is estimated to be above 4.2 sigma . This state is a candidate for the hypothetical exotic Xi --3/2 baryon with S=-2, I=3 / 2, and a quark content of (dsdsu-bar). At the same mass, a peak is observed in the Xi - pi + spectrum which is a candidate for the Xi 03/2 member of this isospin quartet with a quark content of (dsusd-bar). The corresponding antibaryon spectra also show enhancements at the same invariant mass. Christopher Alt; L. Betev; Anja Billmeier; Christoph Blume; Roland Bramm; P. Buncic; Peter Dinkelaker; Dominik Bernhard Flierl; Marek Gazdzicki; Stefan Kniege; Thorsten Kollegger; Christine Meurer; Michael Kosta Mitrovski; R. Renfordt; Reinhard Stock; Herbert Ströbele; Alexander Albert Wetzler; Jacek Zaranek; et al.; NA49 Collaboration article http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/3488 Fri, 14 Oct 2005 17:29:24 +0200