Cross section of the $pp\to K^{+}\hat{I}{\pounds }^{+}n$ reaction close to threshold

Abstract

We have measured inclusive data on $K^{+}$-meson production in $pp$ collisions at COSY Jülich close to the hyperon production threshold and determined the hyperon-nucleon invariant mass spectra. The spectra were decomposed into three parts: $\hat{I}›p$, $\hat{I}{\pounds }^{0}p$ and $\hat{I}{\pounds }^{+}n$. The cross section for the $\hat{I}{\pounds }^{+}n$ channel was found to be much smaller than a previous measurement in that excess energy region. The data together with previous results at higher energies are compatible with a phase space dependence.

accepted by Phys. lett. B some typos corrected