20–25 Aug 2023
Universität Hamburg
Europe/Berlin timezone

The impact of nuclear effect modeling on the cross-section ratio $\nu_e/\nu_\mu$ and its impact for futrue measurements of CP violation

23 Aug 2023, 10:10
20m
Hörsaal J (Historic main building)

Hörsaal J

Historic main building

Edmund-Siemers-Allee 1
Parallel session talk Neutrino Physics T04 Neutrino Physics

Speaker

Till Dieminger (ETH Zurich)

Description

Long-baseline (LBL) neutrino oscillation experiments search for Charge-Parity (CP) violation in the leptonic sector by precisely measuring the $\nu_\mu\to\nu_e$ and $\overline{\nu}_\mu\to\overline{\nu}_e$ appearance probabilities.
One of the dominant systematic uncertainties on the measurements of CP violation, comes from our modeling of the $\nu_e/\overline{\nu}_e$ cross-section ratio, which is subject to a range of uncertainties related to poorly-constrained nuclear physics processes.
Whilst tight constraints on the $\nu_\mu/\overline{\nu}_\mu$ cross-section can be achieved using LBL experiment's near detector data, the lepton mass differences mean that the extrapolation to the $\nu_e/\overline{\nu}_e$ is not trivial.

Currently running LBL experiments reach a sensitivity to exclude the CP conserving hypothesis of about three standard deviations for a relatively large range of $\delta_{CP}$ values, hence a more accurate evaluation of the $\nu_e/\overline{\nu}_e$ related uncertainties becomes increasingly crucial.
Following up on work by Nikolakopoulos et al., we present an analysis quantifying the potential for mis-modeling of the $\nu_\mu/\nu_e, \ \overline{\nu}_\mu / \overline{\nu}_e$ and $\nu_e/\overline{\nu}_e$ cross sections due to nuclear effects as a model spread in the full kinematic phase space for CCQE interactions.
This impact is then propagated to simulated experimental configurations based on the Hyper-K and ESS$\nu$SB experiments.

Significant differences between the theoretical models are found, which largely lie in regions of phase space that contribute only a small portion of the flux integrated cross sections.
Overall, a systematic uncertainty on the oscillated flux-averaged $\nu_e/\overline{\nu}_e$ cross section of $\sim 2$\% and $\sim4$\% is found for the simulated Hyper-K and ESS$\nu$SB experiments respectively.

Collaboration / Activity Independent

Primary author

Till Dieminger (ETH Zurich)

Co-authors

Dr Alexis Nikolakopoulos (Fermilab) Prof. André Rubbia (ETH Zurich) Davide Sgalaberna (ETH Zurich) Dr Luke Pickering (Royal Holloway University of London) Sara Bolognesi (IRFU, CEA Saclay) Stephen Dolan (CERN) Dr Thomas Dealtry (Lancaster University)

Presentation materials