Generalized Complex Spectral Decomposition for a Quantum Decay Process

By extending the notion of mixed states to functionals acting on the space of observables with diagonal singularity we obtain a well-defined complex spectral decomposition of the time evolution for a quantum decaying system. In this formalism, generalized Gamow states are obtained with well-defined physical properties.     

核衰变产生的X射线和俄歇电子数据计算

核衰变过程中,内转换电子发射和电子俘获能在原子电子壳层内留下空穴.其他原子电子壳层的电子将填补这些空穴,其原子电子位置将重排,并发射X射线和俄歇电子.X射线和俄歇电子的能量由原子电子结合能计算得到,X射线和俄歇电子的强度分别由内转换电子发射和电子俘获在原子电子壳层内留下的空穴数,X射线荧光产额,和空穴转移系数计算得到.本文简要介绍核衰变产生的X射线和俄歇电子数据的计算方法、计算程序与工作流程,并以核衰变为例说明其具体应用和简要讨论与总结.     

Double-Beta Decay of 150Nd and 76Ge to Excited States

New results of experimental search for double beta decay of ⁷⁶Ge (2) and ¹⁵⁰Nd (0 + 2) to excited states of the daughter nuclei are presented. Data from 228 days of measurements performed with four HPGe detectors in the low background laboratory of Baksan neutrino observatory yield new limits on life-times T_1/2(0⁺ 0⁺ ₁)6.2×10²¹} yr at 90% C.L. for transition of ⁷⁶Ge to 0⁺ ₁ level of ⁷⁶Se and T_1/2(0⁺ 0⁺ ₁)1.5×10²⁰ yr at 90% C.L. for transition of ¹⁵⁰Nd to 0⁺ ₁ level of ¹⁵⁰Sm.     

(CdZnTe,ZnSeTe)/ZnTe复合量子阱中的超快速激子衰减

为了研究低维半导体结构中的激子过程，并进一步实现超快速的激子衰减，设计了一种新型的(CdZnTe，ZnSeTe)／ZnTe复合量子阱结构，并用低压金属有机化学气相沉积方法(LPMOCVD)制备出来。用泵浦-探测方法，采用反射式光路测量了该复合结构中CdZnTe／ZnTe量子阱的激子衰减。单指数衰减拟合给690fs的下降沿时间。     

无中微子双β衰变相关的中微子势（英文）

介绍了在双β衰变中的闭合近似下的原子核矩阵元,并在此基础上研究了无中微子双β衰变的中微子势部分及统计性质。分析结果显示,费米型和伽莫夫-泰勒型矩阵元部分贡献了几乎相等的正值,并且费米型部分一般比伽莫夫-泰勒型部分的贡献稍大,而张量部分的贡献虽小但不可忽略,其中有少量矩阵元为负。阐明了无中微子双β衰变的中微子势中费米型、伽莫夫-泰勒型及张量部分大于零矩阵元的关联。该统计结果粗略地揭示了这些组份对原子核矩阵元的贡献。Nuclear matrix element in double beta decay under the closure approximation is outlined, in which neutrino potential for neutrinoless double beta decay is studied with focusing on its statistical property. It is shown from the analysis that Fermi and Gamow-Teller parts provide almost the same positive values with the Fermi part slightly larger than the Gamow-Teller part in general, while the tensor part includes small but non-negligible positive and negative values. Positive correlation of the values between Fermi, Gamow-Teller, and tensor parts has been clarified. The statistics provides a gross view of understanding amplitude of constitutional components of the nuclear matrix element.     

Testing CVC and CKM Unitarity via Superallowed Nuclear Beta Decay

Superallowed nuclear beta decay between 0+ analog states is a sensitive probe of the weak interaction, with the established strength – or Ft value – of each such transition being a direct measure of the vector coupling constant, GV. Each transition’s Ft value depends on the half-life of the parent nucleus as well as on the Q-value and branching ratio for the transition of interest. It also depends on small (1%) transition-dependent theoretical corrections, of which the most sensitive accounts for isospin symmetry breaking. We have recently published a new survey of world superallowed-decay data, which establishes the Ft values of 14 separate superallowed transitions to a precision of order 0.1% or better. The results from this very robust data set yield the value of Vud, the up-down quark mixing element of the Cabibbo-Kobayashi-Maskawa (CKM) matrix, and lead to the most demanding test available of CKM unitarity. The survey results and their outcome are described, as is the current direction of experiments that focus on testing the validity of the isospin-symmetry-breaking corrections.     

活化反应截面评价中核衰变数据的作用和影响

就核衰变数据在活化反应截面评价中的作用和影响作了比较详细的介绍,通过几个实例,说明在活化反应截面评价中必须充分考虑核衰变数据的作用和影响.核衰变数据的不准确性有时是造成活化反应截面彼此间分歧的主要原因.     

Neutrinoless Double-Beta Decay to Excited 0+ States Mediated by Light Majorana Neutrinos

The neutrinoless double-beta decay (0 decay) to the first excited 0⁺ collective final state is examined for A = 76, 82, 100 and 136 nuclei by assuming light Majorana neutrino exchange mechanism. Realistic calculations of nuclear matrix elements are performed within the renormalized Quasiparticle Random Phase Approximation. Transitions to the first excited two-quadrupole phonon 0⁺ state are described within a boson expansion formalism. It is found that the ¹⁰⁰Mo is a good candidate for experimental study of the 0 decay to excited 0⁺ state due to small suppression of this transition relative to the transition to the ground state.     

Tsallis Mapping in Growing Complex Networks with Fitness

We introduce Tsallis mapping in Bianconi-Barab'asi (B-B) fitness model of growing networks.This mapping addresses the dynamical behavior of the fitness model within the framework of nonextensive statistics mechanics,which is characterized by a dimensionless nonextensivity parameter q.It is found that this new phenomenological parameter plays an important role in the evolution of networks:the underlying evolving networks may undergo a different phases depending on the q exponents,comparing to the original B-B fitness model,and the corresponding critical transition temperature T C is also identified.     

ε衰变的能量和强度平衡计算

文中给出了ε衰变的能量和强度平衡的计算公式,并以⁵²Mn的ε衰变为例说明其实际应用.     

Continuous Weight Attack on Complex Network

We introduce a continuous weight attack strategy and numerically investigate the effect of continuous weight attack strategy on the Barabasi-Albert （BA） scale-free network and the Erdos-Rdnyi （ER） random network. We use a weight coefficient ω to define the attack intensity. The weight coefficient ω increases continuously from 1 to infinity, where 1 represents no attack and infinity represents complete destructive attack. Our results show that the continuous weight attack on two selected nodes with small ω （ω≈ 3） could achieve the same damage of complete elimination of a single selected node on both BA and ER networks. It is found that the continuous weight attack on a single selected edge with small ω （ω≈ 2） can reach the same effect of complete elimination of a single edge on BA network, but on ER network the damage of the continuous weight attack on a single edge is c/ose to but always smaller than that of complete elimination of edge even if ω is very large.     

Research of Software Defect Prediction Model Based on Complex Network and Graph Neural Network

The goal of software defect prediction is to make predictions by mining the historical data using models. Current software defect prediction models mainly focus on the code features of software modules. However, they ignore the connection between software modules. This paper proposed a software defect prediction framework based on graph neural network from a complex network perspective. Firstly, we consider the software as a graph, where nodes represent the classes, and edges represent the dependencies between the classes. Then, we divide the graph into multiple subgraphs using the community detection algorithm. Thirdly, the representation vectors of the nodes are learned through the improved graph neural network model. Lastly, we use the representation vector of node to classify the software defects. The proposed model is tested on the PROMISE dataset, using two graph convolution methods, based on the spectral domain and spatial domain in the graph neural network. The investigation indicated that both convolution methods showed an improvement in various metrics, such as accuracy, F-measure, and MCC (Matthews correlation coefficient) by 86.6%, 85.8%, and 73.5%, and 87.5%, 85.9%, and 75.5%, respectively. The average improvement of various metrics was noted as 9.0%, 10.5%, and 17.5%, and 6.3%, 7.0%, and 12.1%, respectively, compared with the benchmark models.     

False Vacuum Decay with Gravity in a Critical Case

The vacuum decay in a de Sitter universe is studied for the class of effective inflaton potentials that curvature at the top is less than as well as greater than a critical value determined previously. By comparing the actions of the Hawking - Moss instanton and the Coleman - de Luccia instanton(s) the mode of vacuum decay is determined in this critical situation.     

Revisit to Two-Proton Radioactivity of 19Mg and Observation of Two-Proton Decay of 30Ar

An experiment aimed to investigate the two-proton (2p) decay of the previously unknown nucleus 30Ar was performed at GSI: By tracking the decay products in-flight with silicon micro-strip detectors, the 2p decays of 30Ar were observed for the first time. For the calibration purpose, 2p decays of 19Mg were also remeasured by tracking the coincident 17Ne+p+p trajectories. By comparing the measured angular p-17Ne correlations with those obtained from the corresponding Monte Carlo simulations, the simultaneous 2p decay of 19Mg ground state and the sequential 2p emission of several known excited states of 19Mg were confirmed. One new excited state in 19Mg and two new excited states in 18Na were observed.     

Decay of kaonium in a chiral approach

The decay of the K⁺K⁻ hadronic atom kaonium is investigated non-perturbatively using meson-meson interaction amplitudes taken from leading order chiral perturbation theory in an approach adapted from that proposed by Oller and Oset (1997) [18]. The Kudryavtsev-Popov eigenvalue equation is solved numerically for the energy shift and decay width due to strong interactions in the 1s state. These calculations introduce a cutoff ∼1.4 GeV in O(4) momentum space that is necessary to regulate divergent loop contributions to the meson-meson scattering amplitudes in the strong-interaction sector. One finds lifetimes of (2.2±0.9)×¹⁰−18 s for the ground state of kaonium.     

Complex Network Analysis of Mass Violation,Specifically Mass Killing

News reports in media contain news about society’s social and political conditions. With the help of publicly available digital datasets of events, it is possible to study a complex network of mass violations, i.e., Mass Killings. Multiple approaches have been applied to bring essential insights into the events and involved actors. Power law distribution behavior finds in the tail of actor mention, co-actor mention, and actor degree tells us about the dominant behavior of influential actors that grows their network with time. The United States, France, Israel, and a few other countries have been identified as major players in the propagation of Mass Killing throughout the past 20 years. It is demonstrated that targeting the removal of influential actors may stop the spreading of such conflicting events and help policymakers and organizations. This paper aims to identify and formulate the conflicts with the actor’s perspective at a global level for a period of time. This process is a generalization to be applied to any level of news, i.e., it is not restricted to only the global level.     

131Pm衰变的首次观测

利用³²S轰击¹⁰⁶Cd靶,通过3p4n反应产生了¹³¹Pm,反应产物经过毛细管及带收集传输系统传输到低本底区,测量了反应产物的X,γ单谱,并进行了X-γ,γ-γ符合测量,得到了¹³¹Pm的半衰期及衰变γ线,并建立了简单的衰变纲图.     

Leading Supersymmetric Electroweak Corrections to Top Quark Decay into a Neutralino and Light Stop

We calculate the leading supersymmetric electroweak corrections to t → t₁x_j0 using dimensional reduction scheme within an approximation of low tan β, which can easily be extended to t→x_jb_i. The numerical results show that such corrections can exceed -12% for tan β = 2 and -6% for tan β = 11, respectively. And these corrections vary insensitively with mi, in the region allowed by the kinematics except for ones near the threshold.     

The Decay of 140La to Levels in 140Ce

The decay of ¹⁴⁰La to levels in ¹⁴⁰Ce has been studied in detail using a GMX-Ge and Hp-Ge coincidence spectrometer. Singles gamma-ray spectra as well as gamma-gamma coincidence were carried out to determine some γ-transitions and to insure others. Energies and relative intensities of 36 γ-transitions in the range from 26 to 3319 keV have been measured. The doubted γ-lines 936.7, 1087.9, 1303.5, 1404.2, 1415.3 and 2533.4 keV were confirmed, while other ones at 798.3, 902.0, 907.0, 1521.8 and 2494.0 keV were not observed. The two γ-lines at 1924 and 2082 keV which were a source of large discrepancies in the previous studies are confirmed in the present work to be sum peaks. Special care was paid in identifying the weak γ-transitions 936.7, 1087.9, 1415.3 and 2533.4 keV.

Es wurde der Zerfall von ¹⁴⁰La in Energienivcaus des ^l40Ce unter Verwendung eines GMX-Ge und Hp-Ge-Koinzidenzspeklrometers untersucht. Es werden einzclne Gammaspektren r und Gamma-Gamma-Koinzidenzen aufgenommen, um einige Gamma-Übergänge zu bestimmen und andere abzusichern. Die Energien und die relativen Intcnsitäten von 36 Gamma-Übergangen im Bereich von 26 … 3319 keV wurden vermessen. Die unsicheren Gamma-Linien 936,7, 1087,9, 1303,5, 1404,2, 1415,3 und 2533,4 keV wurden bestätigt, während die Linien 798,3, 902,0, 907,0, 1521,8 und 2494,0 keV nicht beobachtet werden konnten. Die zwei Gamma-Linien bei 1924 und 2082 keV, die eine Quclle groβer Unstimmigkeiten in früheren Untersuchungen gewesen sind, konnten als Summenpeaks bestätigt werden. Besondere Beachtung wurde der Zuordnung der schwachen Gamma-Übergange bei 936,7, 1087,9, 1415,3 und 2533,4 keV geschenkt.     

荧光衰减曲线的一种多指数拟合方法

在荧光衰减测量中，总要遇到荧光衰减解卷积，进行非线性参数拟合问题。目前已有的非线性求极小值方法，都对参数估计值非常敏感，而且计算程序运行时间较长。我们建立了一种基于经典的步长加速法实现非线性最小二乘拟合，进行荧光衰减解卷积的方法，按程序给出参数初值，即能解卷积。