Searching for Beyond the Standard Model Physics with COHERENT Energy and Timing Data

We search for beyond the Standard Model (BSM) physics by combining COHERENT energy and timing data. Focusing on light, $\lesssim$ GeV mediators, we find the data favor a $\sim 10-1000$ MeV mediator as compared to the Standard Model (SM) best fit at the $\lesssim 2\sigma$ level. The best-fit coupling range is $g \sim 10^{-5}-10^{-3}$. The timing data provides statistical information on the neutrino flavor distributions that is not attainable from the nuclear recoil energies alone. This result accounts for uncertainty in the effective size of the neutron distribution, and highlights the power of including uncertainties on experimental backgrounds, nuclear structure, and BSM physics.