Failure of s-channel helicity conservation in A1- production

Abstract

A study of the A1- density-matrix elements shows that s-channel helicity is not conserved in the process π-p→A1-p between 5 and 25 GeVc. Instead the A1- density-matrix elements have simple behavior in the t-channel helicity frame. A new analysis of the A1- cross section as a function of the incident π- momentum is also presented. © 1971 The American Physical Society.