Speaker
Description
Spectroscopic observables in atoms and highly charged ions are sensitive to new scalar-mediated potentials. A scalar with Lorentz-violating couplings allows for a split into "matter" and "antimatter" couplings, at least in the non-relativistic limit. Naively, this requires spectroscopy of both matter and antimatter to disentangle them. In this talk, I will show that relativistic corrections lift this degeneracy already in ordinary hydrogen, giving indirect access to antimatter couplings from matter spectroscopy alone. In highly charged ions, enhanced relativistic effects amplify the sensitivity, compensating for reduced experimental precision and larger theoretical uncertainties. Astrophysical constraints, shown for comparison, provide strong bounds even on antimatter couplings, despite stars being predominantly composed of matter.