C.A. Ayre

Neutron Total Cross-Sections on Nuclei at Fermilab Energies

We have measured total cross sections for neutrons on protons, deuteriom, beryllium, carbon, aluminium, iron, copper, cadmium, tungsten, lead, and uranium for momenta between 30 and 300 GeV/c. The measurements were carried out in a small-angle neutral beam at Fermilab. Typical accuracy of the data is 0.5 to 1%. The cross sections are consistent with an A0.77±0.01 dependence over the entire momentum range. The cross sections are compared with theoretical predictions. Agreement is found only if inelastic screening is included. Nuclear radii obtained from our data are in good agreement with previous determinations.

Neutron-proton differential cross sections in the range 70 to 400 GeV/c

Abstract We report the results of an experiment which measured np elastic scattering differential cross sections over a range in − t from 0.15 to ∼3.6 (GeV/ c ) 2 for incident neutron momenta from 70 to 400 GeV/ c . We find the logarithmic slope parameter, evaluated at − t = 0.2 (GeV/ c ) 2 , to be consistent with existing proton-proton parametrizations. The data exhibit a dip in the cross section near − t = 1.4 (GeV/ c ) 2 for incident neutron momenta above 200 GeV/ c . For neutron momenta less than 280 GeV/ c , the neutron-proton cross sections are found to be higher than existing proton-proton data in the range 0.7 ⩽ − t ⩽ 1.3 (GeV/ c ) 2 which is in contradiction to most Regge predictions.

Comparison of high energy neutron-nucleus total cross sections with theory

A recent paper by Julius purports to show that previous estimates of the effect of inelastic screening on neutron-nucleus total cross sections are much too large. However, we show that most of this discrepancy is due to his using cross sections for diffractwe N* productton which are much too small. The rest may be due to the assumptions in h]s model. We also emphasize that expertmental support for the inelastic screening corrections does not rely on a specific choice of nuclear radii