Evidence for 15O+α resonance structures in 19Ne via direct measurement
Evidence for 15O+α resonance structures in 19Ne via direct measurement
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通过直接测量获得 19Ne 中 15O+α 共振结构的证据
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
C. Spitaleri
中科院分区：
文献类型：
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作者：
D. Torresi;C. Wheldon;T. Kokalova;S. Bailey;A. Boiano;C. Boiano;M. Fisichella;M. Mazzocco;C. Parascandolo;D. Pierroutsakou;E. Strano;M. Zadro;M. Cavallaro;S. Cherubini;N. Curtis;A. Pietro;J. Fernández;P. Figuera;T. Glodariu;J. Grebosz;M. Cognata;M. Commara;M. Lattuada;D. Mengoni;R. Pizzone;C. Signorini;C. Stefanini;L. Stroe;C. Spitaleri
天体物理学上重要的 19Ne 原子核中的状态已通过放射性 15O 光束的 15O(α, α)15O 反应直接填充。由于所涉及的挑战，这代表了第一次此类高分辨率的 15O 测量，也是第一次致力于探索簇结构。该测量包括三个实验：第一个实验是开发 15O 放射性束，第二个实验是共振散射研究，第三个实验是测量 4He 中 O 离子的精确能量损失，以减少系统的不确定性。结果显示了 15O+α 簇结构的证据，这可以解释早期的结果，即高自旋近阈值共振的天体物理反应速率中 α 分支比增加。已测量绝对微分横截面。此外，还使用 R 矩阵分析提取了核反应速率计算所必需的自旋、奇偶校验和部分衰变宽度。
States in the astrophysically important 19Ne nucleus have been populated directly using the 15O(α, α)15O reaction with a radioactive 15O beam. Due to the challenges involved, this represents the first such 15O measurement with high resolution and the first dedicated to exploring the cluster structure. This measurement comprises three experiments: the first to develop the 15O radioactive beam, the second the resonant scattering study, and the third to measure the precise energy loss of O ions in 4He to reduce systematic uncertainties. The results show evidence for 15O+α cluster structure which could explain earlier results pointing to the increased α branching ratio in the astrophysical reaction rate for high-spin near-threshold resonances. Absolute differential cross sections have been measured. Additionally, spins, parities, and partial decay widths, essential for nuclear reaction-rate calculations, have been extracted using an R-matrix analysis.