The recent experimental data obtained by the OBELIX group on pˉ​D and
pˉ​4He total annihilation cross sections are analyzed. The combined
analysis of these data with existing antiprotonic atom data allows, for the
first time, the imaginary parts of the S-wave scattering lengths for the two
nuclei to be extracted. The obtained values are: Ima0sc​=[−0.62±0.02(stat)±0.04(sys)]fm for pˉ​D and Ima0sc​=[−0.36±0.03(stat)−0.11+0.19​(sys)]fm for pˉ​4He. This
analysis indicates an unexpected behaviour of the imaginary part of the
pˉ​-nucleus S-wave scattering length as a function of the atomic weight
A: ∣Ima0sc​∣ (pˉ​p) > ∣Ima0sc​∣ (pˉ​D) > ∣Ima0sc​∣ (pˉ​4He).Comment: 13 pages, 5 figure