Search for a muonphilic scalar X0 or vector X1 via J/ψ →μ+μ-+invisible decays at BESIII

A light scalar X0 or vector X1 particles have been introduced as a possible explanation for the (g-2)μ anomaly and dark matter phenomena. Using (8.998±0.039)×109 J/ψ events collected by the BESIII detector, we search for a light muon philic scalar X0 or vector X1 in the processes J/ψ→μ+μ-X0,1 with X0,1 invisible decays. No obvious signal is found, and the upper limits on the coupling g0,1′ between the muon and the X0,1 particles are set to be between 1.1×10-3 and 1.0×10-2 for the X0,1 mass in the range of 1<M(X0,1)<1000 MeV/c2 at 90% credibility level. © 2024 authors. Published by the American Physical Society.