Neutrino energy reconstruction in quasielastic-like scattering in the MiniBooNE and T2K experiments

作者：Lalakulich O^*; Mosel U; Gallmeister K

来源：Physical Review C, 2012, 86(5): 054606.

DOI：10.1103/PhysRevC.86.054606

Background: Neutrino oscillation probabilities, which are being measured in long-baseline experiments, depend on neutrino energy. The energy in a neutrino beam, however, is broadly smeared so that the neutrino energy in a particular event is not directly known, but must be reconstructed from final state properties. %26lt;br%26gt;Purpose: To investigate the effects of different reaction mechanisms on the energy-reconstruction method widely used in long-baseline neutrino experiments taking also pion production into account, and to clarify how the oscillation signal depends on the energy reconstruction. %26lt;br%26gt;Methods: The Giessen Boltzmann-Uehling-Uhlenbeck (GiBUU) transport model is used for a detailed study of neutrino-nucleus events. %26lt;br%26gt;Results: The difference between the true-QE and QE-like cross sections in the MiniBooNE experiment is investigated in detail. It is shown that fake QE-like events lead to significant distortions in neutrino energy reconstruction. Flux-folded and unfolded cross sections for QE-like scattering are calculated as functions of both true and reconstructed energies. Flux-folded momentum transfer distributions are calculated as functions of both true and reconstructed momentum transfer. Distributions versus reconstructed values are compared with the experimental data. Also presented are the conditional probability densities of finding a true energy for a given reconstructed energy. We show how the energy-reconstruction procedure influences the measurement of oscillation parameters in T2K experiments. %26lt;br%26gt;Conclusions: For the reconstruction procedure based on quasielastic (QE) kinematics all other reaction channels besides true-QE scattering show a shift of the reconstructed energy towards lower values as compared to the true energy. In the MiniBooNE and T2K experiments this shift is about 100-200 MeV and depends on energy. The oscillation signals are similarly affected. These uncertainties may limit the extraction of a CP violating phase from an oscillation result.

• 出版日期2012-11-26