Studies of shell evolution using transfer reactions at ISOLDE

ISOLDE 使用转移反应研究壳演化

• 批准号: 2016552
• 金额: --
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2016552
• 关键词: Studies; shell; evolution; using; transfer

Neutrinoless double beta decay is a currently unobserved process, but has wide implications for many fields in physics if the process is discovered. It would help to determine the absolute masses of each neutrino, and would be an example of the violation of lepton number conservation. An aspect of this process is determining viable nuclei for observing this process. The student will look at single-particle transfer reactions to characterise the cross-sections and occupancies for particular candidate nuclei. These results will then be compared to a number of theoretical calculations of nuclear matrix elements for validation. This will then extend further to using a radioactive beam to identify further candidates. This will make up the first part of the project. The next part of the project will follow onto examining the change in shell structure of isotopes. The spin-orbit interaction shed light on why shell gaps occur, and predicted the correct "magic numbers" for shell closures. However, single-particle state stability is poor, as these magic numbers will change far from the line of stability. Exploring this change in the fundamental structure of the atomic nucleus will help discover and explain new physics phenomena. To that end, transfer reactions will be used at ISOLDE to measure the occupation energies of single-particle orbits to track the evolution of the underlying shell structure. This may move on to using stable targets and radioactive beams to track the structure away from the line of stability.

无中微子双β衰变是目前尚未观测到的过程，但如果发现该过程，将对物理学的许多领域产生广泛的影响。这将有助于确定每个中微子的绝对质量，并将是违反轻子数守恒的一个例子。该过程的一个方面是确定用于观察该过程的可行核。学生将研究单粒子转移反应，以计算特定候选核的截面和占位。然后将这些结果与核基质元素的一些理论计算进行比较，以进行验证。然后，这将进一步扩展到使用放射性束来确定更多的候选人。这将构成该项目的第一部分。该项目的下一部分将继续研究同位素壳结构的变化。自旋-轨道相互作用揭示了壳层间隙发生的原因，并预测了壳层闭合的正确“幻数”。然而，单粒子态的稳定性很差，因为这些幻数会远离稳定线变化。探索原子核基本结构的这种变化将有助于发现和解释新的物理现象。为此，ISOLDE将利用转移反应来测量单粒子轨道的占据能，以跟踪底层壳结构的演变。这可能会转移到使用稳定的目标和放射性束来跟踪远离稳定线的结构。

项目成果

First Exploration of Neutron Shell Structure below Lead and beyond N=126.

• DOI: 10.1103/physrevlett.124.062502
• 发表时间: 2020-01
• 期刊: Physical review letters
• 影响因子: 8.6
• 作者: T. L. Tang;B. Kay;C. Hoffman;J. Schiffer;D. Sharp;L. Gaffney;S. Freeman;M. Mumpower;A. Arokiaraj;E. Baader;P. Butler;W. Catford;G. de Angelis;F. Flavigny;M. Gott;E. Gregor;J. Konki;M. Labiche;I. Lazarus;P. MacGregor;I. Martel;R. Page;Z. Podolyák;O. Poleshchuk;R. Raabe;F. Recchia;J. F. Smith-J. F.-Smith-2127105908;S. Szwec;J. Yang

Evolution of single-particle structure near the N = 20 island of inversion

N = 20 反演岛附近单粒子结构的演化

• DOI: 10.1103/physrevc.104.l051301
• 发表时间: 2021
• 期刊: Physical Review C
• 影响因子: 3.1
• 作者: MacGregor P