Measurement of Spin Parameters for a Decisive Clarification of the Structure Observed in thep−pSystem

Abstract

Recent data are presented on spin-spin correlation parameters $C_{\mathrm{LL}}=(L,L;0,0)$ and $C_{\mathrm{SL}}=(S,L;0,0)$ at forward angles from 1.18 to 2.47 GeV/c incident momenta in proton-proton elastic scattering. Values for $\Delta {\sigma }_L$ (inelastic) are derived and are shown to disagree with predictions of theoretical models attempting to describe $p-p$ scattering without dibaryon resonances. Finally, the $C_{\mathrm{LL}}$ and $C_{\mathrm{SL}}$ data discriminate among various phase-shift solutions, and will lead to a clarification of the $p-p$ phase shifts.