LAUSR

We propose a Standard Model extension by a U(1)R gauge symmetry where only right-handed chiral fermions can carry a non-trivial charge. Here we show that the simplest anomaly-free solution to accommodate the proton charge radius discrepancy takes right-handed muons μR and first generation quarks, uR and dR. Consistency with the latest muon’s (g−2) measurements is achieved through an extra light scalar, which itself must lie in the tens of MeV mass range to be viable.