加入sterile neutrino 去修正A4 model

The Tri-Bimaximal Neutrino Mixing Matrix Could Be Modified By Adding Sterile Neutrinos

馮子耘(Tzu-Yun Feng)

指導教授 ： 張敬民

國立清華大學/理學院/物理學系/碩士(2015年)

https://doi.org/10.6843/NTHU.2015.00241

摘要

微中子震盪實驗已經被量測,從實驗結果得知微中子是有質量的。質量的特徵函數跟味的特徵函數有所不同,中間利用微中子混合矩陣連接。最有名的混合矩陣為TBM 混合矩陣,但是他預測 θ13為零。以現今的實驗數據告訴我們 θ13有95%不為零。所以我們利用加入無效應的微中子去改變 θ13,並且與實驗數據比較。

關鍵字

微中子 ； 混合矩陣

並列摘要

The phenomenon of neutrino oscillation has been established. It implies
that neutrinos having masses, so the mass eigenstate is different with the
flavor eigenstate. They has mixing matrix described by a 3 × 3 unitary matrix,
PMNS, like CKM matrix in quark sector. The most famous pattern is
Tri-Bimaximal mixing matrix which predicts a vanishing θ13, but we have
experimental evidence for a non vanishing value of the smallest θ13. TriBimaximal
mixing matrix needs modifications. We study discrete flavour
symmetries model(A4 symmetry), higher symmetry model and sterile neutrinos
to explain small angle. First, suppose there has A4 symmetry or higher
symmetry in lepton sector and neutrino sector and neutrinos have Majorana
masses(or only have Dirac neutrinos). We will get Tri-Bimaximal mixing
in A4 model. Second, Adding sterile neutrinos modify the mixing matrix,
therefore we could get small angle(θ13). Then, transforming with new mixing
matrix, we found ranges of neutrino masses,mixing angle and so on. We
compare them to the experiment data

並列關鍵字

neutrino ； sterile neutrino

參考文獻

K Asakura, R Ashie, F Berghaus, HG Berns, et al. Measurement

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[2] Guido Altarelli and Ferruccio Feruglio. Tri-bimaximal neutrino mixing

from discrete symmetry in extra dimensions. Nuclear Physics B,

Gavela, and Jacobo L´opez-Pav´on. Unitarity of the leptonic mixing matrix.