162774 20251017144629.0 doi 10.1103/d194-7t6x sideral 145347 ART-2025-145347 eng Rodríguez Candón, Francisco Universidad de Zaragoza Fresh look at the diffuse ALP background from supernovae 2025 Access copy available to the general public Unrestricted Protoneutron stars, highly compact objects formed in the core of exploding supernovae (SNe), are powerful sources of axionlike particles (ALPs). In the SN core, ALPs are dominantly produced via nucleon-nucleon bremsstrahlung and pion conversion, resulting in an energetic ALP spectrum peaked at energies O(100)  MeV. In this work, we revisit the diffuse ALP background, produced from all past core-collapse supernovae, and update the constraints derived from -LAT observations. Assuming the maximum ALP-nucleon coupling allowed by the SN 1987A cooling, we set the upper limit gaγγ≲2×10−13  GeV−1 for ALP mass ma≲10−10  eV, which is approximately a factor of two improvement with respect to the existing bounds. On the other hand, for ma≳10−10  eV, we find that including pion conversion strengthens the bound on gaγγ, approximately by a factor of two compared to the constraint obtained from bremsstrahlung alone. Additionally, we present a sensitivity study for future experiments such as AMEGO-X, e-ASTROGAM, GRAMS-balloon, GRAMS-satellite, and MAST. We find that the expected constraint from MAST would be comparable to -LAT bound. However, SN 1987A constraint remains one order of magnitude stronger as compared to the bound derived from the current and future gamma-ray telescopes. info:eu-repo/grantAgreement/ES/AEI/PID2021-126078NB-C21 info:eu-repo/grantAgreement/EUR/COST/CA21106-COSMIC Wispers info:eu-repo/grantAgreement/EC/H2020/788781/EU/Towards the detection of the axion with the International Axion Observatory/IAXOplus This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No H2020 788781-IAXOplus info:eu-repo/grantAgreement/ES/MINECO/PID2019-108122GB-C31 info:eu-repo/grantAgreement/ES/NextGenerationEU/INVESTIGO-095-28 info:eu-repo/semantics/openAccess by https://creativecommons.org/licenses/by/4.0/deed.es info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Ganguly, Sougata Giannotti, Maurizio Universidad de Zaragoza (orcid)0000-0001-9823-6262 Kumar, Tanmoy Lella, Alessandro Mescia, Federico 2004 038 Universidad de Zaragoza Dpto. Física Teórica Área Astronomía y Astrofísica 2004 390 Universidad de Zaragoza Dpto. Física Teórica Área Física Atóm.Molec.y Nucl. 112, 1 (2025), 015006 [10 pp.] Phys. rev. D Physical Review D 2470-0010 593566 http://zaguan.unizar.es/record/162774/files/texto_completo.pdf Versión publicada 2729135 http://zaguan.unizar.es/record/162774/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:162774 articulos driver 2025-10-17-14:25:21 ARTICLE