Work

Understanding the impact of nuclear effects on proton decay searches with the GiBUU model

Year: 2026

Type: article

Abstract: Proton decay searches in the next generation of water Cherenkov detectors, such as Hyper-Kamiokande, are expected to probe the 10 35 -year lifetime regime where atmospheric neutrino backgrounds and systematic uncertainties begin to play an increasingly important role. In this study, we employ the framework and reevaluate the proton decay search sensitivity for the p → e + π 0 channel by incorporating a typical event reconstruction performance in water Cherenkov detectors. Using sophisticated models implemented in —most notably the mean-field potential and Boltzmann transport—which have been benchmarked against accelerator neutrino scattering data, in particular pion production, we find that the resulting proton decay signal detection efficiency and atmospheric neutrino background rate are comparable to those previously evaluated for the current and near future water Cherenkov experiments using nuclear models. In addition to pion final-state interactions, we evaluate the impact of differences in the Fermi momentum distribution of nucleons in the nucleus, as a source of systematic uncertainty, on the signal detection efficiency and the expected background event rate. We find that the uncertainty associated with pion final-state interactions is moderate, whereas the choice of Fermi momentum distribution can significantly affect the estimated atmospheric neutrino background rate and constitutes the dominant contribution. Our study provides an independent and complementary characterization of nuclear effects on proton decay searches and helps to refine sensitivity estimates in the regime where systematic uncertainties become more relevant.

Source: Physical review. D/Physical review. D.

DOI: 10.1103/zgxd-zy7j

Authors: Qiyu Yan, Akira Takenaka, Kai Gallmeister, Xianguo Lu, Ulrich Mosel, Yangheng Zheng

Institutions: University of Warwick, University of Chinese Academy of Sciences, Sun Yat-sen University, Justus-Liebig-Universität Gießen

Language: English

Topic: Neutrino Physics Research

Subfield: Nuclear and High Energy Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Funder: National Natural Science Foundation of China

Award: G904559116