本文利用冰立方南极中微子观测站，对能量介于0.5至10.0TeV的大气中微子进行了深入研究，特别关注了中微子在传播过程中的相干损失现象。经过分析，研究人员并未发现任何反常的中微子退相干证据，并据此确定了中微子与量子引力相互作用的极限。在能量无关的退相干模型中，研究发现有效退相干强度参数的极限比以前的极限提高了30倍。在退相干效应与E2成比例的情况下，本研究的极限比过去的测量结果提高了6个数量级以上。
据悉，中微子振荡在最高能量和最长基线条件下，可用来深入探索时空结构并验证量子力学的基本原理。若时空度量具备量子力学描述，那么它在普朗克尺度上的波动将可能引入非幺正效应，这与量子力学的标准幺正时间演化相悖。当中微子与这种波动发生相互作用时，其量子相干性将会丧失，导致在远距离和高能量条件下，中微子的振荡味成分与预期产生偏差。
附：英文原文
Title: Search for decoherence from quantum gravity with atmospheric neutrinos
Author: The IceCube Collaboration
Issue&Volume: 2024-03-26
Abstract: Neutrino oscillations at the highest energies and longest baselines can be used to study the structure of spacetime and test the fundamental principles of quantum mechanics. If the metric of spacetime has a quantum mechanical description, its fluctuations at the Planck scale are expected to introduce non-unitary effects that are inconsistent with the standard unitary time evolution of quantum mechanics. Neutrinos interacting with such fluctuations would lose their quantum coherence, deviating from the expected oscillatory flavour composition at long distances and high energies. Here we use atmospheric neutrinos detected by the IceCube South Pole Neutrino Observatory in the energy range of 0.5–10.0TeV to search for coherence loss in neutrino propagation. We find no evidence of anomalous neutrino decoherence and determine limits on neutrino–quantum gravity interactions. The constraint on the effective decoherence strength parameter within an energy-independent decoherence model improves on previous limits by a factor of 30. For decoherence effects scaling as E2, our limits are advanced by more than six orders of magnitude beyond past measurements compared with the state of the art.
DOI: 10.1038/s41567-024-02436-w
Source: https://www.nature.com/articles/s41567-024-02436-w