γ rays from in-flight positron annihilation as a probe of new physics
Year: 2025
Type: article
Abstract: The γ -ray emission originating from in-flight annihilation (IA) of positrons is a powerful observable for constraining high-energy positron production from exotic sources. By comparing diffuse γ -ray observations of INTEGRAL, COMPTEL, and EGRET to theoretical predictions, we set the most stringent constraints on electrophilic feebly interacting particles, thereby proving IA as a valuable probe of new physics. In particular, we extensively discuss the case of MeV-scale sterile neutrinos, where IA sets the most stringent constraints, excluding | U μ 4 | 2 ≳ 10 − 13 and | U τ 4 | 2 ≳ 2 × 10 − 13 for sterile neutrinos mixed with μ and τ neutrinos, respectively. These constraints improve existing limits by more than an order of magnitude. We briefly discuss the application of these results to a host of exotic positron sources such as dark photons, axionlike particles, primordial black holes, and sub-GeV dark matter.
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Funders: Ministerio de Ciencia, Innovación y Universidades, European Commission, European Cooperation in Science and Technology, Vetenskapsrådet, Istituto Nazionale di Fisica Nucleare, Ministero dell'Università e della Ricerca, Science and Technology Facilities Council, Instituto Nazionale di Fisica Nucleare, European Regional Development Fund, Agencia Estatal de Investigación, NextGenerationEU
Awards: G1591695993, G1622782223, G2335788611, G2494670923, G2554159582, Detecting Axion Dark Matter In The Sky And In The Lab, G282847690, Astronomical Signals from Axions and Axion-Like Particles, G3307346093, G3321450376, G3352565690, G3480869486, G3509854106, G5080475149, From the Planck Scale to the Hubble Scale - Theoretical Physics At KCL, G5662822759, G7012770505, G7084143925, G712881263, G7600792, G7805626310, G796431723
OpenAlex ID: W4408226448