arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 0905.4729hep-ph
收藏

非无菌-活性中微子混合:辐射衰变的结果和来自X射线背景的束缚

Unsterile-Active Neutrino Mixing: Consequences on Radiative Decay and Bounds from the X-ray Background

D. Boyanovsky, R. Holman, Jimmy A. Hutasoit

摘要:

我们把无菌中微子看作是一个非粒子,即一个具有反常维数$η$的\emph{unsterile neutrino},并通过一个跷跷板质量矩阵研究了它与正则活动中微子的混合。我们表明,有\emph{no unitary}变换,对角化的混合传播和字段的重新定义是必需的。传播或“质量”状态对应于非无菌和活性模式。非无菌模式的特点是$0 \leq η< 1/3$具有"不可见宽度“的复极点或共振,这是非无菌模式衰减为有源模式和隐藏共形扇区的无质量粒子的结果。对于$η\geq 1/3$,复极点消失,与非粒子阈值合并。主动模式是由一个稳定的极点,但“继承”的非零频谱密度以上的非粒子阈值作为混合的结果。我们发现,未灭菌中微子通过带电电流环衰变为活性中微子(和光子)的\emph{radiative}衰变宽度是\emph{suppressed}的一个因子$\sim \Big[2 \sin^2(θ_0) \frac{M^2}{Λ^2}\Big]^\fracη{1-η}$,其中$θ_0$是$η=0$的混合角,$M$近似为未灭菌中微子的质量,$Λ\gg M$是未粒子尺度.对无菌中微子辐射(可见)衰变宽度的抑制削弱了质量和混合角与X射线或软伽马射线背景的结合。

英文摘要:

We consider a sterile neutrino to be an unparticle, namely an \emph{unsterile neutrino}, with anomalous dimension $η$ and study its mixing with a canonical active neutrino via a see-saw mass matrix. We show that there is \emph{no unitary} transformation that diagonalizes the mixed propagator and a field redefinition is required. The propagating or ``mass'' states correspond to an unsterile-like and active-like mode. The unsterile mode features a complex pole or resonance for $0 \leq η< 1/3$ with an ``invisible width'' which is the result of the decay of the unsterile mode into the active mode and the massless particles of the hidden conformal sector. For $η\geq 1/3$, the complex pole disappears, merging with the unparticle threshold. The active mode is described by a stable pole, but ``inherits'' a non-vanishing spectral density above the unparticle threshold as a consequence of the mixing. We find that the \emph{radiative} decay width of the unsterile neutrino into the active neutrino (and a photon) via charged current loops, is \emph{suppressed} by a factor $\sim \Big[2 \sin^2(θ_0) \frac{M^2}{Λ^2}\Big]^\fracη{1-η}$, where $θ_0$ is the mixing angle for $η=0$, $M$ is approximately the mass of the unsterile neutrino and $Λ\gg M$ is the unparticle-scale. The suppression of the radiative (visible) decay width of the sterile neutrino weakens the bound on the mass and mixing angle from the X-ray or soft gamma-ray background.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑