Measurements of n-p correlations in the reaction of relativistic neon with uranium

Z Phys A At Nucl. 1986:323:391-8. doi: 10.1007/BF01313520.

Abstract

We report a preliminary measurement of coincident neutron-proton pairs emitted at 45 degrees in the interaction of 400, 530, and 650 MeV/A neon beams incident on uranium. Charged particles were identified by time of flight and momentum, as determined in a magnetic spectrometer. Neutral particles were detected using a thick plastic scintillator, and their time of flight was measured between an entrance scintillator, triggered by a charged particle, and the neutron detector. The scatter plots and contour plots of neutron momentum vs. proton momentum appear to show a slight correlation ridge above an uncorrelated background. The projections of this plane on the n-p momentum difference axis are essentially flat, showing a one standard deviation enhancement for each of the three beams energies. At each beam energy, the calculated momentum correlation function for the neutron-proton pairs is enhanced near zero neutron-proton momentum difference by approximately one standard deviation over the expected value for no correlation. This enhancement is expected to occur as a consequence of the attractive final state interaction between the neutron and proton (i.e., virtual or "singlet" deuterons). The implications of these measurements are discussed.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Elementary Particles
  • Models, Theoretical*
  • Neon*
  • Neutrons*
  • Nuclear Physics
  • Protons*
  • Spectrophotometry / methods
  • Uranium*

Substances

  • Protons
  • Uranium
  • Neon