Precision spectroscopy on $^9$Be overcomes limitations from nuclear structure
Stefan Dickopf, Bastian Sikora, Annabelle Kaiser, Marius Müller, Stefan Ulmer, Vladimir A. Yerokhin, Zoltán Harman, Christoph H. Keitel, Andreas Mooser, Klaus Blaum
Many powerful tests of the Standard Model of particle physics and searches for new physics with precision atomic spectroscopy are plagued by our lack of knowledge of nuclear properties. Ideally, such properties may be derived from precise measurements of the most sensitive and theoretically best-understood observables, often found in hydrogen-like systems. While these measurements are abundant for the electric properties of nuclei, they are scarce for the magnetic properties, and precise experimental results are limited to the lightest of nuclei. Here, we focus on $^9$Be which offers the unique possibility to utilize comparisons between different charge states available for high-precision spectroscopy in Penning traps to test theoretical calculations typically obscured by nuclear structure. In particular, we perform the first high-precision spectroscopy of the $1s$ hyperfine and Zeeman structure in hydrogen-like $^9$Be$^{3+}$. We determine its effective Zemach radius with an uncertainty of $500$ ppm, and its bare nuclear magnetic moment with an uncertainty of $0.6$ parts-per-billion (ppb) - uncertainties unmatched beyond hydrogen. Moreover, we compare to measurements conducted on the three-electron charge state $^9$Be$^{+}$, which, for the first time, enables testing the calculation of multi-electron diamagnetic shielding effects of the nuclear magnetic moment at the ppb level. In addition, we test quantum electrodynamics (QED) methods used for the calculation of the hyperfine splitting. Our results serve as a crucial benchmark essential for transferring high-precision results of nuclear magnetic properties across different electronic configurations.
Proposal for the determination of nuclear masses by high-precision spectroscopy of Rydberg states
单电子离子里德伯态的理论处理由于实际上没有核尺寸修正而变得容易，而像里德伯常量这样的基本常数可能在计划中的高精度光谱实验的范围内。因此，在里德伯态之间转移跃迁能量的主要核效应是由于核质量。因此，里德伯跃迁的光谱测量可以用来精确地推断核质量。详细探讨了这种方法在氢和氘以及类氢锂和碳中的可能应用。为了完成主量子数n=5，..态的量子电动力学（QED）自能余项函数的分析、数值和解析计算，8和角动量L=n-1和L=n-2（j = L +/- 1/2）。
Measuring the Variation in Nuclear Charge Radius of Xe Isotopes by EUV Spectroscopy of Highly-Charged Na-like Ions
利用高电荷态类钠离子的极紫外光谱测量了氙同位素核均方电荷半径的变化。在$^{124}$-和$^{136}$-同位素之间的Na-样D1（3s $^{2}$ S $_{1/2}$ -3 p $^2$ P $_{1/2}$）跃迁的同位素位移使用国家标准与技术研究所的电子束离子阱设备实验测定。采用相对论多体微扰理论和多组态Dirac-Hartree-Fock方法计算了质量位移和场位移系数，提高了计算精度。发现均方核电荷半径差为$δ<r^2>^{136, 124}$ = 0.269（0.042）fm $^2$。与已有的实验结果相比，本文的结果具有较小的不确定度，与Angeli和Marinova [I]的推荐值一致。Angeli和K. P. Marinova，At.数据和核数据表{ \bf 99}，69-95（2013）]。
Extreme Ultraviolet Spectroscopy of Highly Charged Lu and Yb Ions for Nuclear Charge Radius Determination
National Institute for Fusion Science（国立核聚变科学研究所）；University of Maryland（马里兰大学）；NASA/GSFC（美国国家航空航天局戈达德太空飞行中心）；The University of Electro-Communications（电波大学）；Clemson University（克莱姆森大学）；University of Debrecen（德布勒森大学）；Massachusetts Institute of Technology（麻省理工学院）；Michigan State University（密歇根州立大学）；Kyushu University（九州大学）
$^{229}$Th Nuclear Spectroscopy in an Opaque Material: Laser-Based Conversion Electron Mössbauer Spectroscopy of $^{229}$ThO$_2$
University of California, Los Angeles（加州大学洛杉矶分校）；University of Manchester（曼彻斯特大学）；University of Nevada, Reno（内华达大学雷诺分校）；Los Alamos National Laboratory（洛斯阿拉莫斯国家实验室）；Eckert & Ziegler Analytics, Inc.（埃克特&齐格勒分析公司）；Johannes Gutenberg-Universität Mainz（美因茨约翰内斯古腾堡大学）；Ludwig-Maximilians-Universität München（慕尼黑路德维希-马克西米利安大学）
Electron-Nuclear Interactions as a Test of Crystal-Field Parameters for Low Symmetry Systems: Zeeman-Hyperfine Spectroscopy of Ho$^{3+}$ Doped Y$_2$SiO$_5$
Hyperfine-Resolved Spectroscopy of Dysprosium Monoxide (DyO) for Precision Measurements of the Nuclear Schiff Moment
Harvard-MIT Center for Ultracold Atoms（哈佛-麻省理工学院超冷原子中心）；Department of Physics, Harvard University（哈佛大学物理系）；Department of Chemistry, Williams College（威廉姆斯学院化学系）；Department of Chemistry, The Johns Hopkins University（约翰斯·霍普金斯大学化学系）
A solid-state nuclear clock based on VUV absorption spectroscopy of $^{229}$Th
Hefei National Laboratory, University of Science and Technology of China（中国科学技术大学合肥国家实验室）；School of Physical Sciences, University of Science and Technology of China（中国科学技术大学物理学院）
Nuclear moments, charge radii, and magnetization distribution parameters of Ag isotopes from laser spectroscopy and \textit{ab initio} electronic-structure calculations
Petersburg Nuclear Physics Institute named by B.P. Konstantinov of National Research Centre “Kurchatov Institute”（以B.P.康斯坦丁诺夫命名的国家研究中心“库尔恰托夫研究所”圣彼得堡核物理研究所）；Saint Petersburg State University（圣彼得堡国立大学）；KU Leuven, Instituut voor Kern- en Stralingsfysica（荷语鲁汶大学核与辐射物理研究所）；Centre for Cold Matter, Imperial College London（伦敦帝国理工学院冷物质中心）；State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University（清华大学物理系低维量子物理国家重点实验室）
Nuclear spin relaxation in zero- to ultralow-field magnetic resonance spectroscopy
New York University（纽约大学）；ELI-NP, “Horia Hulubei” National Institute for Physics and Nuclear Engineering（ELI-NP，“霍里亚·胡鲁贝伊”核物理与核工程国家研究所）；Johannes Gutenberg University of Mainz（美因茨约翰内斯·古腾堡大学）；Helmholtz Institute Mainz（美因茨亥姆霍兹研究所）；University of California, Berkeley（加州大学伯克利分校）
Nuclear Charge Radius of $^9$Be from Muonic Atom Spectroscopy Using a Microcalorimeter
Technion—Israel Institute of Technology（以色列理工学院）；The Helen Diller Quantum Center, Technion—Israel Institute of Technology（海伦·迪勒量子中心，以色列理工学院）；Laboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-PSL Research University, Collège de France（巴黎文理研究大学卡斯特尔-布罗塞尔实验室）；Kirchhoff-Institut für Physik, Universität Heidelberg（海德堡大学基希霍夫物理研究所）；Institut für Kernphysik, Johannes Gutenberg-Universität Mainz（美因茨约翰内斯古腾堡大学核物理研究所）；PRISMA ++ Cluster of Excellence, Johannes Gutenberg-Universität Mainz（美因茨约翰内斯古腾堡大学PRISMA++卓越集群）；The Racah Institute of Physics, The Hebrew University（耶路撒冷希伯来大学拉卡物理学研究所）；KU Leuven, Instituut voor Kern- en Stralingsfysica（荷语鲁汶大学核与辐射物理研究所）
