Reaction pp \( \rightarrow\) pp\( \pi\)\( \pi\)\( \pi\) as a background for hadronic decays of the \( \eta^{{\prime}}_{}\) meson

  • M. J. Zieliński
  • P. Moskal
  • A. Kupść
Open Access
Regular Article - Experimental Physics

DOI: 10.1140/epja/i2011-11093-4

Cite this article as:
Zieliński, M.J., Moskal, P. & Kupść, A. Eur. Phys. J. A (2011) 47: 93. doi:10.1140/epja/i2011-11093-4

Abstract

Isospin violating hadronic decays of the \( \eta\) and \( \eta{^\prime}\) mesons into 3\( \pi\) mesons are driven by a term in the QCD Lagrangian proportional to the mass difference of the d and u quarks. The source giving large yield of the mesons for such decay studies are pp interactions close to the respective kinematical thresholds. The most important physics background for \( \eta\),\( \eta{^\prime}\)\( \rightarrow\)\( \pi\)\( \pi\)\( \pi\) is coming from direct three-pion production reactions. In case of the \( \eta\) meson the background for the decays is relatively low ( \( \approx\) 10% . The purpose of this article is to provide an estimate of the direct pion production background for the \( \eta{^\prime}\)\( \rightarrow\) 3\( \pi\) decays. Using the inclusive data from the COSY-11 experiment we have extracted the differential cross-section for the pp\( \rightarrow\)pp -multipion production reactions with the invariant mass of the pions equal to the \( \eta{^\prime}\) meson mass and estimated an upper limit for the signal to background ratio for studies of the \( \eta{^\prime}\)\( \rightarrow\)\( \pi^{+}_{}\)\( \pi^{-}_{}\)\( \pi^{0}_{}\) decay.

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Copyright information

© SIF, Springer-Verlag Berlin Heidelberg 2011

Authors and Affiliations

  • M. J. Zieliński
    • 1
    • 2
  • P. Moskal
    • 1
    • 2
  • A. Kupść
    • 3
    • 4
  1. 1.Institute of PhysicsJagellonian UniversityCracowPoland
  2. 2.Nuclear Physics InstituteResearch Center JülichJülichGermany
  3. 3.Department of Physics and AstronomyUppsala UniversityUppsalaSweden
  4. 4.High Energy Physics DepartmentThe Andrzej Sołtan Institute for Nuclear StudiesWarsawPoland

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