The implication of $J/ψ\to (γ+ ){\rm invisible}$ for the effective field theories of neutrino and dark matter

Abstract

We study the implication of J/ψ radiative decay into invisible particles for light sterile neutrino and sub-GeV dark matter (DM). The low-energy effective field theories (EFTs) are used for the description of general neutrino interactions and the Dirac fermion DM coupled to charm quark. We perform the likelihood fits for the individual neutrino and DM operators with distinct Lorentz structures and photon spectra. The limits on the decay branching fractions are obtained for different neutrino or DM scenarios and then converted to the lower bounds on the new energy scales. The most stringent bounds on the energy scale in neutrino and DM EFTs are 12.8 GeV and 11.6 GeV, respectively. We also evaluate the limit on the DM-nucleon scattering cross section converted from BESIII data. The BESIII J/ψ data is sensitive to the light DM mass range where the DM direct detection experiments cannot probe yet. The future Super Tau Charm Factory after one year run can push the limits down by two orders of magnitude.

Probing Invisible Vector Meson Decays with NA64 and LDMX

“…Such models generically predict meson decays with missing energy, and several works explored flavor violating decays of B mesons, D mesons, and kaons [4][5][6], and invisible and radiative decays of light flavorless mesons [4,7] and heavy quarkonia [8][9][10][11]. More recently, invisible and radiative decays of light flavorless mesons [12,13] and heavy quarkonia [14][15][16][17][18] into DM have been reconsidered from an effective field theory perspective.…”