New physics via pion capture and simple nuclear reactions

Abstract

Light, beyond-the-standard-model particles $X$ in the 1-100 MeV mass range can be produced in nuclear and hadronic reactions but would have to decay electromagnetically. We show that simple and well-understood low-energy hadronic processes can be used as a tool to study $X$ production and decay. In particular, the pion capture process ${\pi }^{-}p\to Xn\to e^{+}{e}^{-}n$ can be used in a new experimental setup to search for anomalies in the angular distribution of the electron-positron pair, which could signal the appearance of dark photons, axion-like particles and other exotic states. This process can be used to decisively test the hypothesis of a new particle produced in the ${}^7\mathrm{Li}+p$ reaction. We also discuss a variety of other theoretically clean hadronic processes, such as $p+\mathrm{D}(\mathrm{T})$ fusion, as a promising source of $X$ particles.

9 pages, 5 figures, typo in acknowledgments corrected

References in corpus (10)

• Big-Bang Nucleosynthesis
• Secluded U(1) below the weak scale
• Ab initio calculation of the neutron-proton mass difference
• Particle Physics Models for the 17 MeV Anomaly in Beryllium Nuclear Decays
• US Cosmic Visions: New Ideas in Dark Matter 2017: Community Report
• Muonic hydrogen and MeV forces
• New Parity-Violating Muonic Forces
• New weakly-coupled forces hidden in low-energy QCD
• Proton size anomaly
• Dark Photons from Nuclear Transitions

Cited by in corpus (4)

• Dynamical Evidence For a Fifth Force Explanation of the ATOMKI Nuclear Anomalies
• Can a protophobic vector boson explain the ATOMKI anomaly?
• Signals of the QCD axion with mass of 17 MeV/c^2: nuclear transitions and light meson decays
• Revising inelastic dark matter direct detection by including the cosmic ray acceleration