Neutrino CP measurement in the presence of RG running with mismatched momentum transfers

Abstract

The neutrino mixing parameters are expected to have renormalization group (RG) running effect in the presence of new physics. If the momentum transfers at production and detection mismatch with each other, the oscillation probabilities are generally modified and become dependent on not just the neutrino energy but also the momentum transfer. Even in the limit of vanishing baseline, the transition probability for the appearance channel is interestingly not zero. This would significantly affect the sensitivity of the genuine leptonic Dirac CP phase. We further explore the possibility of combining the long- and short-baseline neutrino experiments to constrain such RG running effect for the purpose of guaranteeing the CP measurement. To simulate the double dependence on the neutrino energy and momentum transfer, we extend the usual o simulation of fixed baseline experiments and use a two-dimensional χ2 analysis to obtain sensitivities. Published by the American Physical Society 2024