Measurements have been made of pi+ absorption on He3 at T_pi+ = 118, 162, and 239 MeV using the Large Acceptance Detector System (LADS). The nearly 4pi solid angle coverage of this detector minimizes uncertainties associated with extrapolations over unmeasured regions of phase space. The total absorption cross section is reported. In addition, the total cross section is divided into components in which only two or all three nucleons play a significant role in the process. These are the first direct measurements of the total and three nucleon absorption cross sections.
ABSORPTION CROSS SECTION.
ABSORPTION CROSS SECTION.
Absolute total and differential cross sections for the reaction π++d→p+p have been measured for pion energies from 3.7 to 20.5 MeV. Evidence for p-wave strength was observed for all energies. Using detailed balance and corrections for Coulomb effects, the measured differential and total cross sections were found to be consistent with recent measurements for the reaction n+p→d+π0, offering no evidence for charge-independence breaking. The measured total cross sections for energies below 30 MeV are in disagreement with predictions by Blankleider and by Vogelzang, Bakker, and Boersma.
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