Analysis of zero Pion CC neutrino interactions in ANNIE

• Applicant: Professorin Dr. Caren Hagner
• Subject Area: Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 456139317

The aim of the project is the analysis of the data of the ANNIE experiment with regard to the cross sections of neutrino interactions with charged currents without outgoing pions under consideration of neutron multiplicity. ANNIE is a water Cherenkov detector dopted with gadolinium in the Short Baseline Neutrino Beam at Fermilab. ANNIE's main task is to measure neutrino interactions from this beam, taking advantage of the fact that the gadolinium in the detector allows the number of neutrons produced per event to be determined very well. The cross sections obtained in this way will have a great influence on the energy determination in long-baseline neutrino experiments as well as on the background estimation in diffuse supernova neutrino background and proton decay experiments. Furthermore, they will help to understand which processes within the nuclei influence the number of outgoing pions, and how strongly individual processes, such as pion absorption and so-called 2-particle-2-hole processes, are involved. For this purpose, the measured rates have to be compared with predictions obtained by simulation using different generators. However, for most common neutrino generators this depends on some fine tuning in the software, which differs from experiment to experiment. This is not the case with GIBUU, a generator based on transport theory, which is why it is also to be integrated into ANNIE's simulation software.The proposed postdoc should take a leading role in these analyses and develop the complete analysis chain, starting with data selection, through prediction by simulation, to the calculation of the cross sections. Closely related to this is the use of the already mentioned generator GiBUU for ANNIE, whose predictions are to be used as a comparison. Depending on the speed with which these tasks can be completed, further investigations may follow. That means, that the potential that arises under certain scenarios will be investigated. The first scenario is the irradiation of ANNIE's with anti-neutrinos instead of neutrinos. For the second scenario, it is assumed that water-based liquid scintillator is used as the detector medium instead of water. And in the third scenario we will investigate to what extent it is worthwhile to use the temporal structure of the neutrino beam to break it down into parts with different compositions and energy spectra for analysis.

• DFG Programme: Research Grants