Two-proton correlation function measured at very small relative momenta

Abstract Two-proton coincidences at very small relative momenta were measured in the reaction 129 Xe+ 48 Ti at 45 MeV/nucleon using the SPEG spectrometer at GANIL. From the experimental correlation function, a precise value of the lifetime τ 0 = (3.90±0.15) 10 −21 s is extracted. Applying three angular cuts on the correlation function, a signature of directional effects is observed and a value of the particle source velocity v s = (0.27±0.03)c is deduced in case of a sequential equilibrium emission.