Meson Production in Relativistic Heavy Ion Collisions.
We have measured the inclusive (kappa)(' )production cross sections. at angles from 15(DEGREES) to 80(DEGREES) in collisions of protons (2.1 GeV) and deuterons (2.1 GeV/amu) on NaF and Pb, and Ne (2.1 GeV/amu) on C, NaF, KCl, Cu, and Pb. The kaons were identified by measuring the time of flight and the momentum in a magnetic spectrometer, and by detecting the particles from the kaon decays in a Pb glass Cerenkov counter. The momentum range of the detected kaons extended from 350 MeV/c to 750 MeV/c. The multiplicity of each event was measured by a set of scintillation counter telescopes which were situated around the target. The differential cross section of the kaons falls off exponentially with center of mass energy in the nucleon nucleon center of mass frame. In addition, the angular distribution of the kaons is nearly isotropic in this frame even for p(' )NaF and Ne(' )Pb collisions. The data are compared with a row on row model and a thermal. model. Neither are able to explain all features of the data. The row. on row model does not reproduce the near isotropy in the nucleon. nucleon frame, and the thermal model overpredicts the kaon yield by. a factor of approximately twenty. Analysis of the A dependence shows that the increase in the cross section for kaon production between Ne(' )NaF and Ne(' )Pb collisions is greater than that between d(' )Naf and d(' )Pb. This may be an indication of a collective effect. In Ne(' )Pb collisions the associated multiplicity is approximately 10% higher when a kaon is detected in the spectrometer than when a proton or pion is detected. This indicates that the kaons may come from more central collisions.
- Pub Date:
- Physics: Elementary Particles and High Energy