Evidence for a narrow baryonic state decaying to K0Sp and K0Sp̄ in deep inelastic scattering at HERA

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Erscheinungsjahr:
2004
Medientyp:
Text
Schlagworte:
  • Physics
  • Physics
Beschreibung:
  • A resonance search has been made in the K0Sp and K0Sp̄ invariant-mass spectrum measured with the ZEUS detector at HERA using an integrated luminosity of 121 pb-1. The search was performed in the central rapidity region of inclusive deep inelastic scattering at an ep centre-of-mass energy of 300-318 GeV for exchanged photon virtuality, Q2, above 1 GeV2. Recent results from fixed-target experiments give evidence for a narrow baryon resonance decaying to K+n and K0Sp, interpreted as a pentaquark. The results presented here support the existence of such state, with a mass of 1521.5±1.5(stat.)+2.8-1.7(syst.) MeV and a Gaussian width consistent with the experimental resolution of 2 MeV. The signal is visible at high Q2 and, for Q2>20 GeV2, contains 221±48 events. The probability of a similar signal anywhere in the range 1500-1560 MeV arising from fluctuations of the background is below 6×10-5. © 2004 Elsevier B.V. All rights reserved.
Lizenz:
  • info:eu-repo/semantics/openAccess
Quellsystem:
Forschungsinformationssystem der UHH
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Quelldatensatz
oai:www.edit.fis.uni-hamburg.de:publications/cf0c1c9a-1462-4734-bb39-61cc37977618