Pion absorption in 3He at 37 Mev

We studied the 3He(π+,pp)p and 3He(π-,pn)n reactions at 37 MeV at TRIUMF. The outgoing protons were detected with NaI(Tl) detectors and the coincident protons (neutrons) with an array of plastic scintillator. The angular distributions for the absorption of a pion on two nucleons were determined. For the 3He(π+,pp)p reaction, the cross section shape is similar to that of d(π+,pp), while the magnitude is about 1.5 times larger (7.9 ± 0.7 mb). For the 3He(π-, pn)n reaction, the differential cross sections (with respect to the detected proton) are asymmetric about 90 degrees in the π-pp center-of-mass system, with the probability higher for proton emission at backward angles. The magnitude of the cross section is 0.85 ± 0.15mb. The present data are at the lowest energy compared to previous pion absorption on 3He. One expects from recent theoretical studies that low energy absorption is of particular interest for probing short-range nucleon- nucleon correlations. Our cross section results for π+ and π- are similar to those obtained at higher energies