title: Constraint on parity-violating muonic forces.
abstract: Using the nonobservance of missing mass events in the leptonic kaon decay K→μX, we place a strong constraint on exotic parity-violating gauge interactions of the right-handed muon. By way of illustration, we apply it to an explanation of the proton size anomaly that invokes such a new force; scenarios in which the gauge boson decays invisibly or is long lived are constrained.
authors.affiliation: Department of Physics, University of Wisconsin, Madison, Wisconsin 53706, USA.
authors.forename: Vernon
authors.initials: V
authors.lastname: Barger
authors.forename: Cheng-Wei
authors.initials: CW
authors.lastname: Chiang
authors.forename: Wai-Yee
authors.initials: WY
authors.lastname: Keung
authors.forename: Danny
authors.initials: D
authors.lastname: Marfatia