Search for the dark photon in ${\pi }^0$ decays

Abstract

A sample of $1.69\times 10^7$ fully reconstructed ${\pi }^0\to \gamma e^{+}{e}^{-}$ decay candidates collected by the NA48/2 experiment at CERN in 2003--2004 is analysed to search for the dark photon ($A^{\prime }$) production in the ${\pi }^0\to \gamma A^{\prime }$ decay followed by the prompt $A^{\prime }\to e^{+}{e}^{-}$ decay. No signal is observed, and an exclusion region in the plane of the dark photon mass $m_{A^{\prime }}$ and mixing parameter ${\epsilon }^2$ is established. The obtained upper limits on ${\epsilon }^2$ are more stringent than the previous limits in the mass range $9\mathrm{MeV}/c^2<m_{A^{\prime }}<70\mathrm{MeV}/c^2$. The NA48/2 sensitivity to the dark photon production in the $K^{\pm }\to {\pi }^{\pm }{A}^{\prime }$ decay is also evaluated.

arXiv commentRevised version accepted for publication in Physics Letter B

Cited by in corpus (19)

• Supernova 1987A Constraints on Sub-GeV Dark Sectors, Millicharged Particles, the QCD Axion, and an Axion-like Particle
• Strong Constraints on Sub-GeV Dark Matter from SLAC Beam Dump E137
• Lepton flavor violating Z' explanation of the muon anomalous magnetic moment
• Dark photons from charm mesons at LHCb
• The Search for Feebly-Interacting Particles
• Precision tests of fundamental physics with $\eta$ and ${\eta }^{\prime }$ mesons
• New light mediators for the $R_K$ and $R_{K^{\ast }}$ puzzles
• New Prospects in Fixed Target Searches for Dark Forces with the SeaQuest Experiment at Fermilab
• Boosted Self-interacting Dark Matter in a Multi-component Dark Matter Model
• Probing the Dark Sector with Dark Matter Bound States
• Implication of the hidden sub-GeV bosons for the $(g-2{)}_{\mu }$, ${}^8$Be-${}^4$He anomaly, proton charge radius, EDM of fermions and dark axion portal
• Hunting down massless dark photons in kaon physics
• The 17 MeV Anomaly in Beryllium Decays and $U(1)$ Portal to Dark Matter
• Examining the origin of dark matter mass at colliders
• Searching for new light gauge bosons at $e^{+}{e}^{-}$ colliders
• Tests of the Atomki anomaly in lepton pair decays of heavy mesons
• On the stability of the open-string QED neutron and dark matter
• Interpretation of XENON1T excess with MeV boosted dark matter
• LHC experiments for long-lived particles of the dark sector