Eur. Phys. J. A (2011) 47: 93
https://doi.org/10.1140/epja/i2011-11093-4

Regular Article - Experimental Physics

Reaction pp pp as a background for hadronic decays of the meson

¹ Institute of Physics, Jagellonian University, PL-30-059, Cracow, Poland
² Nuclear Physics Institute, Research Center Jülich, D-52425, Jülich, Germany
³ Department of Physics and Astronomy, Uppsala University, Box 516, 75121, Uppsala, Sweden
⁴ High Energy Physics Department, The Andrzej Sołtan Institute for Nuclear Studies, Hoża 69, PL-00681, Warsaw, Poland

Received: 18 March 2011
Accepted: 19 July 2011
Published online: 9 August 2011

Abstract

Isospin violating hadronic decays of the and mesons into 3 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 , is coming from direct three-pion production reactions. In case of the meson the background for the decays is relatively low ( 10% . The purpose of this article is to provide an estimate of the direct pion production background for the 3 decays. Using the inclusive data from the COSY-11 experiment we have extracted the differential cross-section for the pp pp -multipion production reactions with the invariant mass of the pions equal to the meson mass and estimated an upper limit for the signal to background ratio for studies of the decay.