Testing the very-short-baseline neutrino anomalies at the solar sector
Testing the very-short-baseline neutrino anomalies at the solar sector
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DOI：
10.1103/physrevd.83.113013
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发表时间：
2011-05
影响因子：
5
通讯作者：
A. Palazzo
中科院分区：
文献类型：
--
作者：
A. Palazzo
在eV尺度的新的不育中微子物种的积累提示的动机，我们探索这样一个假设对太阳扇区现象学的后果。在介绍了描述太阳中微子在远离（nu_1，nu_2）“双重态”的一个（或多个）无菌中微子态存在下MSW转换所需的理论形式之后，我们对现有的实验结果进行了定量分析，重点是电子中微子混合。我们发现，目前的数据对轻子混合矩阵元U_e4的振幅敏感--它编码电子中微子与新的质量本征态的混合--这与标准矩阵元U_e3的结果相当。此外，更重要的是，我们的分析表明，在4味框架中，目前对|U_e3|>0与对于|U_e4|>0，具有相似的统计显著性（采用旧的反应堆通量测定值为~ 1.3 sigma，采用新的估计值为~ 1.8 sigma）。我们还指出，与标准的3味情况不同，在3+1方案中，狄拉克CP破坏阶段不能从太阳中微子转换的描述中消除。
Motivated by the accumulating hints of new sterile neutrino species at the eV scale, we explore the consequences of such an hypothesis on the solar sector phenomenology. After introducing the theoretical formalism needed to describe the MSW conversion of solar neutrinos in the presence of one (or more) sterile neutrino state(s) located "far" from the (nu_1,nu_2) "doublet", we perform a quantitative analysis of the available experimental results, focusing on the electron neutrino mixing. We find that the present data posses a sensitivity to the amplitude of the lepton mixing matrix element U_e4 --- encoding the admixture of the electron neutrino with a new mass eigenstate --- which is comparable to that achieved on the standard matrix element U_e3. In addition, and more importantly, our analysis evidences that, in a 4-flavor framework, the current preference for |U_e3|>0 is indistinguishable from that for |U_e4|>0, having both a similar statistical significance (which is ~ 1.3 sigma adopting the old reactor fluxes determinations, and ~ 1.8 sigma using their new estimates). We also point out that, differently from the standard 3-flavor case, in a 3+1 scheme the Dirac CP-violating phases cannot be eliminated from the description of solar neutrino conversions.