Observation of an exotic S = -2, Q = -2 baryon resonance in proton proton collisions at the CERN SPS
Oct, 2003Citations per year
Abstract: (arXiv)
Results of resonance searches in the Xi- pi-, Xi- pi+, antiXi+ pi- and antiXi+ 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/c^2 and width below the detector resolution of about 0.018 GeV/c^2. The significance is estimated to be 4.0 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 (d s d s ubar). At the same mass a peak is observed in the Xi- pi+ spectrum which is a candidate for the Xi_(3/2)^0 member of this isospin quartet with a quark content of (d s u s dbar). The corresponding antibaryon spectra also show enhancements at the same invariant mass.Note:
- 5 pages, 3 figures
- p p: inclusive reaction
- baryon resonance: hadroproduction
- baryon resonance: exotic
- strangeness: -2
- charge: -2
- pentaquark
- baryon resonance: hadronic decay
- Xi
- pi
- mass spectrum: (p pi-)
References(16)
Figures(3)