The influence of parton structure on hadronic interactions in EHS with a $K^{+}$/$\pi^{+}/p$ beam at 250 GeV/c

The aim of the experiment is to study the following topics: a) The influence of parton structure on low p^t hadron-hadron collisions. b) Strangeness flow and correlations in fragmentation. c) Meson-Nucleus collisions. The data are expected to throw light on the still uncalculable (soft) quark fragmentation mechanism, in particular when the 'tagged' strange quark of the K|+ beam is involved as parent quark.\\ \\ The experiment is done with the European Hybrid Spectrometer which has a large geometrical acceptance combined with good momentum resolution and with very powerful particle identification. The general layout is shown in the Figure. With a very general trigger, a wealth of reactions will be accumulated, which will permit a detailed study of an umbiased sample of events. For all topics of physics under study, it is highly desirable and for some even absolutely essential that the experimental set-up contains the forward Cerenkov detector and th radiation detector. For topic c), the rapid cycling bubble chamber RCBC is equipped with thin metallic foils. \\ \\ A kaon enriched positive beam is used of as high a momentum as possible, fulfilling the requirement of a kaon content $>$10\%.