π⁻-induced production of K⁰Λ pairs on nuclei at 1.15 GeV/c momentum

Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland

^a e-mail: adam.kasparek@gmail.com

Abstract

In this article we present study of π⁻ induced production of K⁰Λ pairs on nuclei at 1.15 GeV/c momentum. Experiment was performed at FOPI spectrometer in GSI in Germany. In order to differentiate the K⁰Λ pair production in single-step (π⁻p → K⁰Λ) from multi-step (π⁻N → … → K⁰Λ) processes, the missing mass (MM) analysis was performed. The spectra of MM for C and Pb targets show two prominent structures at positive (around m_p) and negative values. For single-step process π⁻p → K⁰Λ a broad peak somewhat the proton mass (m_p) was expected and it is observed. The Monte-Carlo simulations of two-step process π⁻N → R, RN → NK⁰Λ lead to formation of broad structure at negative MM and positive MM peak close to m_p. The evolution of the observed structure can be interpreted as increase of the role of multi-step process with the target mass.