Programme

P.3 -- Posters, VCTP-51

Date: Tuesday, 4 August 2026

Time: 09:30 - 10:30

Fourier transformation for non-parametric CPT testing with neutrino oscillation data

Cam-Vi Le (1), Son Cao (1)

(1) Institute for Interdisciplinary Research in Science and Education (IFIRSE, ICISE)

CPT invariance is a fundamental principle of quantum field theory, and its verification in the neutrino sector is essential since neutrinos have the smallest mass among leptons. Conventional analyses of neutrino oscillation data typically rely on model-dependent parameter fitting, which may introduce biases and potentially obscure subtle differences between neutrino and antineutrino behaviors. Here we propose a novel CPT-invariance testing using a non-parametric Fast Fourier Transform (FFT) approach. Our method can apply directly on the measurable ratio of the oscillated to unoscillated event rate spectra in the L/E domain, extracting phase position and amplitude of spectral peaks corresponding to $\Delta m^2_{31}$ and leptonic mixing angles in the standard picture. Statistical uncertainties are rigorously handled through Monte Carlo sampling with Poisson fluctuations. A major focus of this work is validating the robustness of the frequency extraction algorithm under high-statistics conditions. We evaluate the algorithm's accuracy in handling propagated errors and discuss the expected sensitivity of this FFT-based technique. This method provides a robust, model-independent complementary tool for probing CPT violation in future precision neutrino experiments such as Hyper-Kamiokande in Japan and DUNE in the US

Presenter: Lê Cẩm Vi