$V_0$ Inclusive Production Cross Sections

Neutral strangeness production is an important probe for the study of fragmentation processes. Two-body decays $K^0_S\, \rightarrow\pi^+ \pi^-$, $\Lambda\, \rightarrow p \pi^-$, $\bar \Lambda\, \rightarrow \bar p \pi^+$ can easily be identified due to abundant production, large branching ratios and long lifetime. These particles are labeled as '$V_0$ decays'. The tracks of the decay products look like the letter ``V'' on bubble chamber photos when they were first discovered.

In this chapter a measurement of the $V_0$ production cross section of HERA-B is presented. The cross sections per nucleus are transformed to cross sections per nucleon and compared to previous measurements. The analysis is performed with the minimum bias data taken in December 2002 with three different target materials (C,Ti and W).