Volume 639, July 2020
|Number of page(s)||14|
|Published online||09 July 2020|
Galactic halo size in the light of recent AMS-02 data
LPSC, Université Grenoble Alpes, CNRS/IN2P3, 53 avenue des Martyrs, 38026 Grenoble, France
2 Instituto de Física Teórica UAM/CSIC, Calle Nicolás Cabrera 13-15, Cantoblanco 28049 Madrid, Spain
3 Niels Bohr International Academy & Discovery Center, Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100 Copenhagen, Denmark
4 LUPM, CNRS & Université de Montpellier (UMR-5299), Place Eugène Bataillon, 34095 Montpellier Cedex 05, France
5 LAPTh, Université Savoie Mont Blanc & CNRS, 74941 Annecy Cedex, France
Accepted: 14 May 2020
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 10Be/Be data, and we performed a consistency check with positron data. We detail the dependence of Be/B and 10Be/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 10Be/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 10Be/9Be 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.
Key words: astroparticle physics / cosmic rays / Galaxy: halo
© N. Weinrich et al. 2020
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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