Speaker
Description
Next generation neutrino oscillation experiments, such as JUNO, DUNE, and
Hyper-Kamiokande, are positioned to collect unprecedented statistics in neutrino
data, enabling high-precision measurements of oscillation parameters. A major
fraction of the data will consist of atmospheric neutrinos, which allows for
independently extracting oscillation parameters and placing constraints on
neutrino mass ordering by probing the MSW parametric resonance. To make best use
of the data, it is essential to understand and improve the current modelling of
atmospheric neutrino fluxes and their uncertainties.
The Bartol model is a Monte Carlo simulation-based atmospheric neutrino flux
model created in the 1980s for calculating the unoscillated flux at terrestrial
detectors. The original model has become significantly outdated as it uses
physics models which do not reflect recent experimental measurements on e.g.
hadron production cross section or primary cosmic ray fluxes with drastically
improved uncertainties. The geomagnetic field model likewise needs to be updated
to include around 20 years of geomagnetic field observations. In the context of
DSNB searches, there is growing interest in <100 MeV atmospheric neutrino
fluxes, which is outside of the energy range described by the original Bartol
model.
To accommodate for updates to the Bartol model, the codebase has been fully
redesigned from the ground up to facilitate model development. I will
demonstrate that predictions from the new simulation are consistent with
previous results from the Bartol model and cover recent progress towards
addressing the shortcomings of the original Bartol model.
