Theoretical Calculations for the Models of Phosphorus Clusters P_(10)

[中文文摘]用分子图形学方法设计出26种P10模型，并对其进行了分子力学、PM3半经验量子化学和Hartree－Fock从头算优化．在P10原子团簇模型设计中，磷原子采用一、二、三或四配位．大部分P10的模型是在P9+和P8的模型上分别增加1、2个原子生成的．这些模型包括15种在势能面上局域极小点和11种鞍点（或过渡态）．从模型优化后的能量比较可知，2个四面体P4与1个P2通过4个单键连接的桥式结构最稳定．从最稳定楔状P8可以派生多种构型，其中有一种的能量也相当低。由正四面体P4和楔状P8派生出的结构具有能量优势，它们是构造大分子磷原子团簇的重要的结构基元．在模型几何优化中，得到了带有2个一配位原子的特殊结构，它含有2个三键（1.95）。[英文文摘]Twenty-six P10 models were acquired with molecular graphics and then carried out the optimizations with molecular mechanics, PM3 semi-empirical and ab intio calculations.The phosphorus atoms could be in one-fold, two -fold, three-fold and four-fold in these models. Most of models are designed by adding one or two atoms in the P8 and P9+ clusters. Fifteen models having local minimum on the potential-energy surface are showed. Eleven models (the saddle point or the tiansitive state) having negative eigenvalue also be displayed.From compreing the total energies of the different models, the structures derived from the tetrahedral P4 by connecting P2 with four single bonds are favor in the total energy.Many models can be derived from cuneane P8 by addint two-fold atoms, one of them is quite stable also.The tetrahedral P4 and the cuneane P8 play the important roles in the compositions of the large phosphorus clusters.Aspecial sturcture containing two one-fold atoms, two triple bond (1.95),was obtained after geometry optimization.The total energies of negative eigenvalue are nomally higher than the local minimum.国家自然科学基金重大课题和国家自然科学基金(29573117)

The Possibilities of the Isomers for Phosphorus Clusters P_6

[中文文摘]使用分子图形学方法设计出 2 3种可能的同分异构体 ,并对其进行了分子力学、PM3半经验量子化学和 ADF密度泛函优化。在 P6原子团簇模型设计中 ,磷原子采用一、二、三或四配位。从各异构体的比较可得知 ,由正四面体 P4派生出的结构在能量方面具有优势。椅式结构、船式结构和平面结构的能量依次增大.[英文文摘]We acquired twenty three P 6 isomers with molecular graphics and then carried out the optimizations with molecular mechanics, PM3 semi empirical and ADF density functional calculations. When designing these isomers, the phosphorus atoms could be in one fold, two fold, three fold, four fold. From comparing the bonding energies of the different isomers, the structures derived from the most stable P 4 by adding two phosphorus atoms are favor in bonding energy. The bonding energy increases in the sequences of chair, boat and plane structures.国家自然科学基金重大课题; 国家自然科学基金!(2 95 73117)

The possibilities of the isomers for phosphorus clusters P-6

We acquired twenty-three P-6 isomers with molecular graphics and then carried out the optimizations with molecular mechanics, PM3 semi-empirical and ADF density functional calculations. When designing these isomers, the phosphorus atoms could be in one-fold, two-fold, three-fold, four-fold. From comparing the bonding energies of the different isomers, the structures derived from the most stable P-4 by adding two phosphorus atoms are favor in bonding energy. The bonding energy increases in the sequences of chair, boat and plane structures

Measurement of integrated luminosity of data collected at 3.773 GeV by BESIII from 2021 to 2024

We present a measurement of the integrated luminosity e+e- of collision data collected by the BESIII detector at the BEPCII collider at a center-of-mass energy of Ecm = 3.773 GeV. The integrated luminosities of the datasets taken from December 2021 to June 2022, from November 2022 to June 2023, and from October 2023 to February 2024 were determined to be 4.995±0.019 fb-1, 8.157±0.031 fb-1, and 4.191±0.016 fb-1, respectively, by analyzing large angle Bhabha scattering events. The uncertainties are dominated by systematic effects, and the statistical uncertainties are negligible. Our results provide essential input for future analyses and precision measurements

Prediction of Energy Resolution in the JUNO Experiment

International audienceThis paper presents the energy resolution study in the JUNO experiment, incorporating the latest knowledge acquired during the detector construction phase. The determination of neutrino mass ordering in JUNO requires an exceptional energy resolution better than 3% at 1 MeV. To achieve this ambitious goal, significant efforts have been undertaken in the design and production of the key components of the JUNO detector. Various factors affecting the detection of inverse beta decay signals have an impact on the energy resolution, extending beyond the statistical fluctuations of the detected number of photons, such as the properties of liquid scintillator, performance of photomultiplier tubes, and the energy reconstruction algorithm. To account for these effects, a full JUNO simulation and reconstruction approach is employed. This enables the modeling of all relevant effects and the evaluation of associated inputs to accurately estimate the energy resolution. The study reveals an energy resolution of 2.95% at 1 MeV. Furthermore, the study assesses the contribution of major effects to the overall energy resolution budget. This analysis serves as a reference for interpreting future measurements of energy resolution during JUNO data taking. Moreover, it provides a guideline in comprehending the energy resolution characteristics of liquid scintillator-based detectors

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

Determination of the number of ψ(3686) events taken at BESIII

The number of ψ(3686) events collected by the BESIII detector during the 2021 run period is determined to be (2259.3±11.1)×106 by counting inclusive ψ(3686) hadronic events. The uncertainty is systematic and the statistical uncertainty is negligible. Meanwhile, the numbers of ψ(3686) events collected during the 2009 and 2012 run periods are updated to be (107.7±0.6)×106 and (345.4±2.6)×106, respectively. Both numbers are consistent with the previous measurements within one standard deviation. The total number of ψ(3686) events in the three data samples is (2712.4±14.3)×10^