What experimental evidence do we have that leptons (electrons, muons, tau leptons, neutrinos) create—rather than merely respond to—a gravitational field?
General relativity (GR) predicts that all forms of mass-energy gravitate, that is, generate a curvature of spacetime proportional to their associated energy-momentum tensor. GR has yet to be empirically contradicted, so we have strong theoretical expectations here. My question is about the status of experimental evidence for this prediction.
Massless photons empirically feel gravitation, seen in gravitational lensing. I am aware of the concepts of active and passive gravitational mass. Whether experimental evidence exists for creation of a gravitational field by photons has been addressed (Do photons bend spacetime or not?); in summary, as I understand it, we do not yet know.
What about leptons? The charged leptons (electrons etc.) would seem to be the most promising candidates given that they have far greater mass than neutrinos and photons.
A related question (Active gravitational mass of the electron) was asked nearly a decade ago, and does not address other leptons or recent advances.