We present a model-independent approach to electric quadrupole transitions of deformed nuclei. Based on an effective theory for axially symmetric systems, the leading interactions with electromagnetic fields enter as minimal couplings to gauge potentials, while subleading corrections employ gauge-invariant non-minimal couplings. This approach yields transition operators that are consistent with the Hamiltonian, and the power counting of the effective theory provides us with theoretical uncertainty estimates. We successfully test the effective theory in homonuclear molecules that exhibit a large separation of scales. For ground-state band transitions of rotational nuclei, the effective theory describes data well within theoretical uncertainties at leading order. In order to probe the theory at subleading order, data with higher precision would be valuable. For transitional nuclei, next-to-leading order calculations and the high-precision data are consistent within the theoretical uncertainty estimates. We also study the faint inter-band transitions within the effective theory and focus on the $E2$ transitions from the $0^+_2$ band (the "$β$ band") to the ground-state band. Here, the predictions from the effective theory are consistent with data for several nuclei, thereby proposing a solution to a long-standing challenge.
Quantum effects in the quadrupole rotor picture of ultra-relativistic ion-ion collisions
CEA, DES, IRESNE, DER, SPRC, LEPh（法国原子能及替代能源委员会）；School of Physics and Astronomy, Sun Yat-sen University（中山大学物理学院）；Guangdong Provincial Key Laboratory of Quantum Metrology and Sensing, Sun Yat-Sen University（中山大学广东省量子计量与传感重点实验室）；Technische Universität Darmstadt（达姆施塔特工业大学）；Université Paris-Saclay – CEA – IRFU（巴黎萨克雷大学-法国原子能及替代能源委员会-核物理研究所）；Yukawa Institute for Theoretical Physics, Kyoto University（京都大学汤川理论物理研究所）
A microscopic quantum ideal rotor-model Hamiltonian (distinct from that of Bohr's rotational model) is derived for a rotation about a single axis by applying a dynamic rotation operator to the deformed nuclear ground-state wavefunction. It is shown that the microscopic ideal rotor Hamiltonian is obtained only for a rigid-flow prescription for the rotation angle, with the attendant rigid-flow kinematic moment of inertia. (For the center-of-mass motion, the method predicts the correct mass.) Using Hartree-Fock variational and second quantization methods, the ideal rotor-model Hamiltonian is redu…
We develop an effective field theory (EFT) for deformed odd-mass nuclei. These are described as an axially symmetric core to which a nucleon is coupled. In the coordinate system fixed to the core the nucleon is subject to an axially symmetric potential. Power counting is based on the separation of scales between low-lying rotations and higher-lying states of the core. In leading order, core and nucleon are coupled by universal derivative terms. These comprise a covariant derivative and gauge potentials which account for Coriolis forces and relate to Berry-phase phenomena. At leading order, the…
The wobbling spectrum of $^{163}$Lu is described through a novel approach, starting from a triaxial rotor model within a semi-classical picture, and obtaining a new set of equations for all four rotational bands that have wobbling character. Redefining the band structure in the present model is done by adopting the concepts of Signature Partner Bands and Parity Partner Bands. Indeed, describing a wobbling spectrum in an even-odd nucleus through signature and parity quantum numbers is an inedited interpretation of the triaxial super-deformed bands.
The Confined beta-Soft rotor model in rare-earth nuclei
National and Kapodistrian University of Athens（雅典国立卡波季斯特里安大学）；Institute of Nuclear and Particle Physics, National Centre for Scientific Research ``Demokritos''（德莫克里斯国家科学研究中心核与粒子物理研究所）
Triaxially deformed relativistic point-coupling model for $Λ$ hypernuclei: a quantitative analysis of hyperon impurity effect on nuclear collective properties
Superdeformed band in the $N = Z+4$ nucleus $^{40}$Ar: A projected shell model analysis
实验上确认的$^{40}$ Ar [E. Ideguchi等人，Phys. Lett. B 686（2010）18]具有轴向或三轴变形的形状。投影壳模型计算与角动量投影使用轴向变形的基础上进行高自旋。我们计算的能级表明，一个完美的集体转子行为的超形变yrast带。然而，详细分析的波函数表明，高自旋结构是由混合0，2，和4准粒子配置为主。计算的电四极跃迁几率再现以及已知的实验数据，并建议减少，但仍然显着，集体在高自旋区域。推导出的三轴变形参数是小的，在整个带，这表明三轴性是不是很重要的超变形带。
Odd-even mass differences of well and rigidly deformed nuclei in the rare earth region: A test of a newly proposed fit of average pairing matrix elements
