Constraints on light vector mediators through coherent elastic neutrino nucleus scattering data from COHERENT

We present new constraints on three different models, the so-called universal, $B-L$ and $L_mu-L_tau$ models, involving a yet to be observed light vector $Z$ mediator, by exploiting the recent observation of coherent elastic neutrino-nucleus scattering (CE$ u$NS) in argon and cesium-iodide performed by the COHERENT Collaboration. We compare the results obtained from a combination of the above data sets with the limits derived from searches in fixed target, accelerator, solar neutrino and reactor CE$ u$NS experiments, and with the parameter region that could explain the anomalous magnetic moment of the muon. We show that for the universal and the $B-L$ models, the COHERENT data allow us to put stringent limits in the light vector mediator mass, $M_{Z}$, and coupling, $g_{Z}$, parameter space.