利用原子游離以尋找微中子電磁性質和暗物質

Detection of neutrino electromagnetic properties and dark matter via atomic ionization

吳致樑(Chih-Liang Wu)

指導教授 ： 陳俊瑋

國立臺灣大學/理學院/物理研究所/碩士(2014年)

https://doi.org/10.6342/NTU.2014.02255

摘要

隨著探測器技術的發展，原子游離已經被視為可能的管道以尋找微中子電磁性質以及暗物質。我們使用一個具有解析解的簡單模型──氫原子，考慮其透過不同的交互作用後被游離，將微分截面的結果與數種近似法比較，來尋找原子結構對於這些過程的影響以及這些近似法的適用性。在實驗上，其中一個探測方法是以鍺原子當作標靶，測量被游離電子產生的訊號，我們透過第一原理計算的理論: 多重組態相對論性混相理論與應用，來處理鍺原子游離的過程，由此得到的結果與氫原子得到的結論相互驗證並發現有許多相似之處。本研究主要的目標為提供比以前的近似法更為可信而的計算，藉由國聖核電廠產生微中子的能譜以及探測器偵測的結果，得到對於微中子電磁性質的上限。

關鍵字

微中子,暗物質,鍺原子,原子游離,相對論性混相理論,自由電子近似,等效光子近似

並列摘要

With the advent of detectors with sub-keV sensitivities, atomic ionization of detectors has been identified as a promising avenue to probe possible neutrino electromagnetic properties and light dark matter. We begin with the process involving ionization of hydrogen, a few-body toy model that has analytic result, by different interactions and compare the result with several approximations often used in atomic physics in oder to study possible influence of atomic structure and the applicabilities of various approximations from this simple case. Next, with the use of an ab initio calculation, multiconfiguration relativistic random-phase approximation theory (MCRRPA), we are able to study practical detectors like germanium (Ge). The general features being found from hydrogen is useful for cases where Ge detectors are considered. The main goal is to provide more reliable cross section results with reasonable theoretical error estimation than the conventionally used formula. Based on the spectrum from the Kuo-Shen Nuclear Power Station, constraints of neutrino electromagnetic properties are obtained.

並列關鍵字

neutrino,dark matter,germanium,ionization,random phase approximation,free electron approximation,equivalent photon approximation

參考文獻

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