Ref Arxiv: 2004.00441
DOI: 10.1051/0004-6361/202038064
Ref. & Cit.: NASA ADS
2 citations
Résumé:

Context. The vertical diffusive halo size of the Galaxy, $L$, is a key parameter for dark matter indirect searches. It can be better determined thanks to recent AMS-02 data. Aims. We set constraints on $L$ from Be/B and $^{10}$Be/Be data, and we performed a consistency check with positron data. We detail the dependence of Be/B and $^{10}$Be/Be on $L$ and forecast on which energy range better data would be helpful for future $L$ improvements. Methods. We used USINE V3.5 for the propagation of nuclei, and e+ were calculated with the pinching method. Results. The current AMS-02 Be/B (∼3% precision) and ACE-CRIS $^(10)$Be/Be (∼10% precision) data bring similar and consistent constraints on $L$. The AMS-02 Be/B data alone constrain $L = 5_{−2}^{+3}$ kpc at a 68% confidence level (spanning different benchmark transport configurations), a range for which most models do not overproduce positrons. Future experiments need to deliver percent-level accuracy on 10Be/9Be anywhere below 10 GV to further constrain $L$. Conclusions. Forthcoming AMS-02, HELIX, and PAMELA $^{10}Be/$^{9}$Be results will further test and possibly tighten the limits derived here. Elemental ratios involving radioactive species with different lifetimes (e.g. Al/Mg and Cl/Ar) are also awaited to provide complementary and robuster constraints.