DETERMINATION OF NEUTRON-NEUTRON SCATTERING LENGTH FROM REACTION PI-+D-]2N+GAMMA

The photon energy spectrum from the reaction π-+d→2n+γ at zero energy has been measured by a pair spectrometer using accoustic spark chambers to locate the pair-electron tracks. From the shape of the spectrum the neutron-neutron scattering length was determined to be ann=13.1+2.4-3.4. The probability of existence of a bound state of two neutrons was calculated to be less than 5 × 10-9. © 1968 The American Physical Society.