[论文解读] Neutrinos, DUNE and the world best bound on CPT violation

Gabriela Barenboim, M. Tórtola+1 more|arXiv (Cornell University)|Dec 5, 2017

Neutrino Physics Research被引用 6

一句话总结

本文提出，中微子振荡实验，特别是DUNE，可将世界最佳CPT破坏界限显著提高几个数量级。利用当前中微子数据和DUNE的灵敏度，若T2K的近期结果成立，则CPT破坏可在超过3σ的水平上被探测到，DUNE对Δ(Δm²₃₁)的界限改善至少一个数量级。

ABSTRACT

CPT symmetry, the combination of Charge Conjugation, Parity and Time reversal, is a cornerstone of our model building strategy and therefore the repercussions of its potential violation will severely threaten the most extended tool we currently use to describe physics, i.e. local relativistic quantum fields. However, limits on its conservation from the Kaon system look indeed imposing. In this work we will show that neutrino oscillation experiments can improve this limit by several orders of magnitude and therefore are an ideal tool to explore the foundations of our approach to Nature. In order to do that we calculate the current CPT bound on all the neutrino mixing parameters and study the sensitivity of the DUNE experiment to such a violation. After deriving the most updated bound on CPT from neutrino oscillation data, we show that, if the recent T2K results turn out to be the true values of neutrino and antineutrino oscillations, DUNE would measure CPT violation at more than 3$\sigma$. Then, we study the sensitivity of the experiment to measure CPT violation in general, finding that DUNE will be able to improve the current bounds on $\Delta(\Delta m^2_{31})$ by at least one order of magnitude. We also study the sensitivity to the other oscillation parameters. Finally we show that, if CPT is violated in nature, combining neutrino with antineutrino data in oscillation analysis will produce imposter solutions.

研究动机与目标

• 利用中微子振荡数据改进当前世界最佳CPT破坏界限。
• 评估DUNE实验对中微子混合参数中CPT破坏的灵敏度。
• 研究当CPT被破坏时，结合中微子与反中微子数据的影响。
• 量化对Δ(Δm²₃₁)及其他振荡参数灵敏度的预期提升。

提出的方法

• 分析当前中微子振荡数据，以推导CPT破坏的最新界限。
• 利用DUNE实验的预期灵敏度，评估中微子与反中微子振荡中的CPT破坏。
• 比较中微子与反中微子振荡概率，以探测混合参数中CPT破坏的差异。
• 使用Δχ²分析和置信区间，对CPT破坏的灵敏度进行统计评估。
• 模拟当CPT被破坏时，结合中微子与反中微子数据所导致的虚假解。

实验结果

研究问题

• RQ1 中微子振荡实验能否将当前CPT破坏界限提高几个数量级？
• RQ2 若T2K的近期结果正确，DUNE实验探测CPT破坏的灵敏度如何？
• RQ3 与当前限制相比，DUNE在Δ(Δm²₃₁)界限上的改善程度有多大？
• RQ4 当CPT被破坏且同时使用中微子与反中微子数据时，对振荡分析有何影响？

主要发现

• 若近期T2K结果真实反映了中微子与反中微子振荡的参数值，DUNE将在超过3σ的水平上测量到CPT破坏。
• DUNE预计可将当前Δ(Δm²₃₁)界限至少提高一个数量级。
• DUNE对其他振荡参数中CPT破坏的灵敏度也显著增强。
• 当CPT被破坏时，结合中微子与反中微子数据会导致分析中出现虚假解。