NuFit-6.0：三味中微子振荡的更新全局分析
NuFit-6.0: Updated global analysis of three-flavor neutrino oscillations
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中文总结 AI 辅助
本研究发布NuFit-6.0三味中微子振荡全局更新分析，测定了多个振荡参数精度，分析了质量序与CP相位的关联及数据分歧，补充Super-K数据后正序获Δχ²=6.1支持，并更新了绝对中微子质量相关参数范围。
中文摘要 AI 辅助
我们呈现了截至2024年9月的中微子振荡数据更新全局分析。参数$θ_{12}$、$θ_{13}$、$Δm^2_{21}$和$|Δm^2_{3\rl}|$（$\rl = 1,2$）已得到良好测定，其3σ相对精度分别约为13%、8%、15%和6%。第三混合角$θ_{23}$仍存在八分圆歧义，尚无明确迹象表明其大于或小于$45^\rl$。轻子CP相位$δ_{CP}$的测定取决于中微子质量序：对于正序，全局拟合在1σ范围内与CP守恒一致；而对于倒序，约$270^\rl$的$δ_{CP}$CP破坏值相比CP守恒以超过3.6σ的置信度被更青睐。尽管现有数据原则上对中微子质量序有2.5–3σ的灵敏度，但全局数据中存在的不同趋势降低了区分能力：T2K和NOvA的出现数据各自更支持正序，但二者在倒序下彼此更一致。相反，由全局消失数据联合测定的$|Δm^2_{3\rl}|$更偏好正序。总体而言，包含长基线、反应堆和IceCube大气数据的全局拟合对两种质量序的拟合效果几乎相当。仅当将Super-Kamiokande的大气中微子数据$χ^2$表加入我们的$χ^2$分析时，全局拟合才以$Δχ^2 = 6.1$的结果偏好正序。我们还提供了对β衰变、无中微子双β衰变和宇宙学中绝对中微子质量敏感的有效参数的更新范围与相关性。
英文摘要
We present an updated global analysis of neutrino oscillation data as of September 2024. The parameters $θ_{12}$, $θ_{13}$, $Δm^2_{21}$, and $|Δm^2_{3\ell}|$ ($\ell = 1,2$) are well-determined with relative precision at $3σ$ of about 13\%, 8\%, 15\%, and 6\%, respectively. The third mixing angle $θ_{23}$ still suffers from the octant ambiguity, with no clear indication of whether it is larger or smaller than $45^\circ$. The determination of the leptonic CP phase $δ_{CP}$ depends on the neutrino mass ordering: for normal ordering the global fit is consistent with CP conservation within $1σ$, whereas for inverted ordering CP-violating values of $δ_{CP}$ around $270^\circ$ are favored against CP conservation at more than $3.6σ$. While the present data has in principle $2.5$--$3σ$ sensitivity to the neutrino mass ordering, there are different tendencies in the global data that reduce the discrimination power: T2K and NOvA appearance data individually favor normal ordering, but they are more consistent with each other for inverted ordering. Conversely, the joint determination of $|Δm^2_{3\ell}|$ from global disappearance data prefers normal ordering. Altogether, the global fit including long-baseline, reactor and IceCube atmospheric data results into an almost equally good fit for both orderings. Only when the $χ^2$ table for atmospheric neutrino data from Super-Kamiokande is added to our $χ^2$, the global fit prefers normal ordering with $Δχ^2 = 6.1$. We provide also updated ranges and correlations for the effective parameters sensitive to the absolute neutrino mass from $β$-decay, neutrinoless double-beta decay, and cosmology.
