Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Antiproton annihilation on light nuclei at very low energies   The recent experimental data obtained by the OBELIX group on $\bar{p}$D and
$\bar{p}^4$He 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: $Im a^{sc}_0 = [- 0.62 \pm
0.02 ({stat}) \pm 0.04 ({sys})] fm$ for $\bar{p}$D and $Im a^{sc}_0 = [-
0.36\pm 0.03({stat})^{+0.19}_{-0.11}({sys})] fm$ for $\bar{p}^4$He. This
analysis indicates an unexpected behaviour of the imaginary part of the
$\bar{p}$-nucleus S-wave scattering length as a function of the atomic weight
A: $|Im a^{sc}_0|$ ($\bar{p}$p) > $|Im a^{sc}_0|$ ($\bar{p}$D) > $|Im
a^{sc}_0|$ ($\bar{p}^4$He).

2
The categories of this paper are: math
24
The categories of this paper are: dg-ga
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
17
The categories of this paper are: q-fin
19
The categories of this paper are: eess
26
The categories of this paper are: bayes-an
4
The categories of this paper are: cond-mat
11
The categories of this paper are: hep-lat
13
The categories of this paper are: quant-ph
28
The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph
35
The categories of this paper are: mtrl-th
3
The categories of this paper are: physics
23
The categories of this paper are: solv-int
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The categories of this paper are: gr-qc