Projected Sensitivity to Atmospheric Neutrino Oscillations using a 1725 m3 Liquid-Nitrogen Detector at CJPL
Abstract
In atmospheric neutrino analyses, the usable zenith-angle range is generally restricted to upward-going events to suppress the cosmic-ray muon background. Motivated by the exceptionally low underground muon background at the China Jinping Underground Laboratory (CJPL), we investigate whether extending the zenith-angle acceptance can improve the sensitivity of atmospheric neutrino oscillation measurements. An existing 1725 m3 liquid-nitrogen volume is adopted as the basis of a simplified detector model, in which the accepted zenith-angle range is extended from cosθμ∈[−1,0] to cosθμ∈[−1,0.3], and the projected oscillation sensitivity is evaluated for a 10-year exposure. The atmospheric neutrino flux is estimated by interpolating standard flux predictions as a function of geomagnetic latitude. Neutrino interactions in the surrounding rock and the liquid-nitrogen volume are simulated for neutrino energies of E≥0.1 GeV, followed by secondary-particle transport and geometry-based event selection. For the benchmark oscillation parameters Δm232 = 2.4×10−3 eV2 and sin2θ23=0.5, the neutrino-induced muon flux from the surrounding rock is estimated to be (3.65 ± 1.00)×10−13 cm−2 s−1 sr−1, corresponding to a muon yield of (0.13 ± 0.034) day−1 in the 1725 m3 liquid-nitrogen volume. Three-flavor neutrino oscillations are incorporated into a Poisson-likelihood χ2 analysis to evaluate the sensitivity to the oscillation parameters. Extending the usable zenith-angle range leads to a clear improvement in the projected oscillation sensitivity at the 90\% confidence level over a 10-year exposure.
Related
- Atmospheric Neutrino Oscillations: the Full Picture
- When can decoherence reveal a Majorana phase? A phase-covariance no-go theorem for two-flavor neutrino oscillations
- Quantum field-theoretical description of solar neutrino oscillations
- Neutrino Oscillations without Mass: A Re-analysis of KamLAND Data following the Dirac Equation in Curved Spacetime
- Probing damping effects in neutrino oscillations with 207 days of JUNO data
BibTeX
@misc{peng2026projected,
title = {{Projected Sensitivity to Atmospheric Neutrino Oscillations using a 1725 m$^3$ Liquid-Nitrogen Detector at CJPL}},
author = {Xiao-Yu Peng and Shin-Ted Lin and Shu-Kui Liu and Hao-Yang Xing and Jing-Jun Zhu and Han-Yu Li and Bi-Jun Xiao and Li-Tao Yang and Qian Yue and Muhammed Deniz},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.39251},
eprint = {2609.39251},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.39251},
}
RIS
TY - UNPB
TI - Projected Sensitivity to Atmospheric Neutrino Oscillations using a 1725 m^3 Liquid-Nitrogen Detector at CJPL
AU - Xiao-Yu Peng
AU - Shin-Ted Lin
AU - Shu-Kui Liu
AU - Hao-Yang Xing
AU - Jing-Jun Zhu
AU - Han-Yu Li
AU - Bi-Jun Xiao
AU - Li-Tao Yang
AU - Qian Yue
AU - Muhammed Deniz
PY - 2026
DA - 2026/09/30
PB - arXiv
DO - 10.48550/arxiv.2609.39251
UR - https://arxiv.org/abs/2609.39251
AB - In atmospheric neutrino analyses, the usable zenith-angle range is generally restricted to upward-going events to suppress the cosmic-ray muon background. Motivated by the exceptionally low underground muon background at the China Jinping Underground Laboratory (CJPL), we investigate whether extending the zenith-angle acceptance can improve the sensitivity of atmospheric neutrino oscillation measurements. An existing 1725 m^3 liquid-nitrogen volume is adopted as the basis of a simplified detector model, in which the accepted zenith-angle range is extended from cosθ_μ∈[−1,0] to cosθ_μ∈[−1,0.3], and the projected oscillation sensitivity is evaluated for a 10-year exposure. The atmospheric neutrino flux is estimated by interpolating standard flux predictions as a function of geomagnetic latitude. Neutrino interactions in the surrounding rock and the liquid-nitrogen volume are simulated for neutrino energies of E≥0.1 GeV, followed by secondary-particle transport and geometry-based event selection. For the benchmark oscillation parameters Δm^2_32 = 2.4×10^−3 eV^2 and sin^2θ_23=0.5, the neutrino-induced muon flux from the surrounding rock is estimated to be (3.65 ± 1.00)×10^−13 cm^−2 s^−1 sr^−1, corresponding to a muon yield of (0.13 ± 0.034) day^−1 in the 1725 m^3 liquid-nitrogen volume. Three-flavor neutrino oscillations are incorporated into a Poisson-likelihood χ^2 analysis to evaluate the sensitivity to the oscillation parameters. Extending the usable zenith-angle range leads to a clear improvement in the projected oscillation sensitivity at the 90\% confidence level over a 10-year exposure.
ER -