arXiv subjects

Seisho Abe

Publications and source records attributed to Seisho Abe.

5 recordsLinked to original sources

arXiv2026

Benchmarking neutrino-nucleus quasielastic scattering model predictions against a missing energy profile obtained using a monoenergetic neutrino beam

We examine three exclusive nuclear ground state shell models implemented in the NEUT neutrino event generator and benchmark them against the recent JSNS$^2$ measurement of missing energy using a monoenergetic neutrino source. The nature of the measurement allows a detailed investigation of nuclear ground-state modeling using a neutrino source, and gives access to a direct measurement of the neutron spectral function in a $^{12}$C nucleus. The NEUT intranuclear cascade and nuclear deexcitation \textsc{NucDeEx} are used to simulate inelastic final-state interactions and nuclear deexcitations respectively. We find that the spectral function (SF) models perform better than relativistic mean field models in modeling both the ground state and the tail of the missing energy distribution when the NEUT cascade and nuclear excitation channels are turned on. We also find that taking into account the missing energy threshold for single nucleon knockout interactions results in all nuclear models being accepted based on the obtained $p$-values.

hep-ex↗

arXiv2025

Benchmarks and applications of the nuclear deexcitation event generator NucDeEx

Neutron multiplicity is a key observable in recent neutrino experiments that can enhance the sensitivity of various neutrino physics searches. Nuclear deexcitation plays a significant role in neutron emissions associated with neutrino-nucleus interactions. Therefore, precise prediction of this process is essential. To address this need, a general-purpose nuclear deexcitation event generator \textsc{NucDeEx} was developed and released as an open-source package. The treatment of low-lying discrete excited states was updated to better reproduce experimental data. Benchmarks were conducted using existing nuclear deexcitation event generators and experimental data. Application to other simulators, neutrino event generator \textsc{NEUT} and general particle simulation tool \textsc{Geant4}, are also presented.

hep-ex↗

arXiv2024

Implementation and investigation of electron-nucleus scattering in the \textsc{NEUT} neutrino event generator

Understanding nuclear effects is essential for improving the sensitivity of neutrino oscillation measurements. Validating nuclear models solely through neutrino scattering data is challenging due to limited statistics and the broad energy spectrum of neutrinos. In contrast, electron scattering experiments provide abundant high-precision data with various monochromatic energies and angles. Since both neutrinos and electrons interact via electroweak interactions, the same nuclear models can be applied to simulate both interactions. Thus, high-precision electron scattering data is essential for validating the nuclear models used in neutrino experiments. To enable this, the author has introduced a new electron scattering framework in the \textsc{NEUT} neutrino event generator, covering two interaction modes: quasielastic (QE) and single pion production. \textsc{NEUT} predictions of QE agree well with numerical calculations, supporting the validity of this implementation. From comparisons with \textsc{NEUT} predictions and inclusive electron scattering data, the momentum-dependent removal energy correction is derived, addressing effects beyond the plane wave impulse approximation. This correction is applied to neutrino interactions, observing significant changes in charged lepton kinematics. Notably, the reconstructed neutrino energy distribution shows a peak shift of approximately 20--30\,MeV, which is crucial for accurately measuring neutrino oscillation parameters.

hep-ph↗

arXiv2024

Combined Pre-Supernova Alert System with Kamland and Super-Kamiokande

Preceding a core-collapse supernova, various processes produce an increasing amount of neutrinos of all flavors characterized by mounting energies from the interior of massive stars. Among them, the electron antineutrinos are potentially detectable by terrestrial neutrino experiments such as KamLAND and Super-Kamiokande via inverse beta decay interactions. Once these pre-supernova neutrinos are observed, an early warning of the upcoming core-collapse supernova can be provided. In light of this, KamLAND and Super-Kamiokande, both located in the Kamioka mine in Japan, have been monitoring pre-supernova neutrinos since 2015 and 2021, respectively. Recently, we performed a joint study between KamLAND and Super-Kamiokande on pre-supernova neutrino detection. A pre-supernova alert system combining the KamLAND detector and the Super-Kamiokande detector was developed and put into operation, which can provide a supernova alert to the astrophysics community. Fully leveraging the complementary properties of these two detectors, the combined alert is expected to resolve a pre-supernova neutrino signal from a 15 M$_{\odot}$ star within 510 pc of the Earth, at a significance level corresponding to a false alarm rate of no more than 1 per century. For a Betelgeuse-like model with optimistic parameters, it can provide early warnings up to 12 hours in advance.

hep-ex↗

arXiv2023

Nuclear deexcitation simulator for neutrino interactions and nucleon decays of $^{12}\text{C}$ and $^{16}\text{O}$ based on TALYS

Nuclear deexcitation associated with neutrino interactions and nucleon decays has a significant impact on a recent key observable for neutrino detectors: neutron multiplicity. However, most existing neutrino Monte Carlo event generators do not consider this process. For a comprehensive prediction of the neutron multiplicity, a nuclear deexcitation simulator based on TALYS named NucDeEx is developed. NucDeEx can be used for neutrino interactions and nucleon decayes for $^{12}\text{C}$ and $^{16}\text{O}$. The author provides the NucDeEx codes and sample codes for applying the NucDeex to widely-used neutrino Monte Carlo event generators, NEUT, NuWro, and GENIE.

hep-ph↗