Determination of the absolute momentum of a high-energy hadron beam using elastic scattering of hadrons from a helium target

Abstract In a small-angle elastic scattering experiment (NA8) in the H8 beam of the CERN Super Proton Synchrotron, the absolute momentum of the incident beam particles has been determined from data on hadron— 4 He elastic scattering. Measurements were performed at beam momenta ranging from 100 GeV/ c to 300 GeV/ c , and the average absolute momentum was determined with a precision of 0.15%. This method can be applied also at higher energies.