The polarization of 3He elastically scattered from 27Al and 28Si at 21 MeV

The polarization of 21 MeV ³He elastically scattered from ²⁷Al and ²⁸Si has been measured in an angular range of θ_lab = 25°–55°. Differential cross-section data have been obtained out to angles of approximately 100°. The small values observed in the polarization distributions differ somewhat from optical-model predictions based on fits to the differential cross-section data and cannot be used to obtain significant information about the optical-model spin-orbit potential. It is concluded that statistically significant, non-zero ³He polarization measurements will not be possible using traditional double scattering techniques for ³He energies ≦ 27 MeV and targets of $\text{Z ≧ 13}$.     

Evidence for a high mass enhancement in K+K− photoproduction

The reaction γp → K⁺K^? p has been investigated with tagged photons in the energy range of 20 < E_γ < 70 GeV. A structure in the 1.7 GeV mass region is observed and interpreted in terms of a recurrence of the ø.     

Dissociation of the photon to π+π−π0π0 and ωπ0 states

New measurements of 4π systems, produced by electron-positron annihilation and τ-decay, are analysed in terms of interfering contributions from two ρ′-mesons, ρ′₁ and ρ′₂, and from the tail of the ρ-meson decaying into two-body states. Separation into orthogonal 4π states, corresponding to different symmetrized isotopic spin wave-functions, is a central feature of the analysis. It is found that the major decay of the ρ′₁ is into a 4π state of class [31] and that the major production of 4π states of class [211] for 4π masses below 1.5 GeV is due to the tail of the ρ decaying to ωπ and, probably, toh ₁π. Nothing new can be inferred about the decays of ρ′₂, and specific needs for improved data are indicated.     

A two stage model for the transition process in perpendicular magnetic recording

An improved analytical model for the transition region of perpendicular magnetic recording is presented. Analytical relationships between all model parameters and head, medium and head-medium interface parameters are established. A comparison is presented between the single transition readout waveform obtained experimentally and that calculated by the new model. The agreement is satisfying.