Search for production of an invisible dark photon in $π^0$ decays

@misc{collaboration2019searchproductioninvisible,
      title={Search for production of an invisible dark photon in $π^0$ decays},
      author={NA62 collaboration},
      year={2019},
      eprint={1903.08767},
      archivePrefix={arXiv},
      primaryClass={hep-ex},
      url={https://arxiv.org/abs/1903.08767},
}