Phase space dependence of the multiplicity distribution in π+ andpp collisions at 250 GeV/c

The charged particle multiplicity distribution has been studied for non-single-diffractive π⁺ p andpp collisions at \(\sqrt s = 22\) GeV, for full phase space as well as for intervals in rapidity, azimuthal angle and transverse momentum. In general, the multiplicity distribution is well described by a negative binomial. From comparison of the distribution for negative or positive particles to that of all charged particles, cascading is favoured as an interpretation over stimulated emission. Interesting consequences follow from a comparison of our results to those at collider energies and toe ⁺ e ^? data at comparable energy. Furthermore, evidence is given that the multiplicity distribution is not exactly of negative binomial type in every (connected or disconnected) phase space region.     

Resonant coupling of optical phonons to J-multiplet excitations in intermediate valent Sm0.75Y0.25S

An anomalous splitting of theJ=0J=1 multiplet transition has been observed by magnetic neutron scattering from intermediate valent Sm_0.75Y_0.25S. The splitting is discussed in terms of a resonant coupling of optical phonons to the magnetic exciton built from the localizedJ=0J=1 multiplet transition by magnetic intersite coupling.