BESIII实验的物理目标是对𝜏-粲能区进行精确测量。准确可靠的粒子鉴别系统对于提高信噪比，尤其是K/$\pi$鉴别至关重要。基于塑料闪烁体的飞行时间探测器是BESIII实验用于粒子鉴别的重要工具。测量时间利用BhaBha事例作为刻度样本，通过对依赖于时幅和击中位置的经验公式修正得到，预期时间通过径迹外推得到，测量时间与预期时间差值即为时间差$\Delta...
正在建设的CSR外靶实验（CEE）时间投影室（TPC）用于研究高密度核物质的设计和构建。CEE TPC是在CEE进行的实验研究中至关重要的探测器，将用于研究核物质的相结构和超饱和密度下的冷非对称核物质状态方程。TPC的设计旨在为带电粒子提供轨迹信息，包括三维位置、动量、电荷和能量损失。
TPC是高能和核物理实验中常用的探测器。它由一个充满气体或液体的敏感体积组成，粒子电离产生的电子可以在电场中漂移。通过观察电子到达读出平面的位置，可以确定电离位置的二维信息，而第三维信息（漂移长度）可以通过漂移时间计算得出。CEE TPC计划成为中国迄今为止最大的TPC，体积约为1立方米。
CEE...
CEPC的现有气体探测器在1-2 GeV低能区的k/pi、k/p分辨能力下降明显，这将严重影响味物理研究的潜能，模拟发现使用飞行时间探测器提供的飞行时间信息将可极大提高其分辨能力。因此CEPC决定选择基于AC-LGAD技术为粒子提供50皮秒的时间分辨，CEPC将在桶部和端盖处放置飞行时间探测器。设计成条状的单层AC-LGAD还将为粒子提供在Phi方向10微米的位置分辨，z方向1微米位置分辨。即为CEPC提供带电粒子的时间和位置信息的4维探测能力，对CEPC上的味物理研究有重要意义。
In this research, we investigate the influence of nuclear structure parameters on the collective flow observed in symmetric and asymmetric nuclear collisions at ultra-relativistic energies. Our approach involves introducing an approximate yet realistic analytical model for the collision process, which allows us to emphasize the pivotal role played by the structural characteristics of the...
Recently, there has been a growing focus on the search for anomalous objects beyond standard model (BSM) signatures at the Large Hadron Collider (LHC). This study investigates novel signatures involving highly collimated photons, referred to as photon-jets. These photon-jets can be generated from highly boosted BSM particles that decay into two or more collimated photons in the final state....
The measurement of the magnetic field created in high-energy heavy-ion collisions is challenging, due to the fact that the magnetic field decays so drastically that in a thermalized quark-gluon plasma the field strength becomes rather weak. By incorporating the weak magnetic effect into the medium, and especially into the production formalism of dileptons from the quark-gluon plasma, the...
Measurements of the production of heavy-flavour hadrons in proton–proton (pp) collisions provide an important test of quantum chromodynamics (QCD).
The heavy-flavour production cross section can be calculated using the factorisation approach as a convolution of three factors: the parton distribution functions (PDFs), the partonic cross section calculated with perturbative QCD calculations,...
基于声子探测的新型荧光-热量两维读出低温晶体量热器技术，具有高能量分辨率和独特粒子鉴别能力，在低本底测量、稀有核衰变寻找等领域极具竞争力。
报告主要介绍以BGO为核心吸收体的光-热两维读出晶体量热器研制，通过mK深冷低温测试，介绍针对BGO低温晶体量热器的最佳工作点的选取，基线的稳定性修正以及光热符合分析等；结果给出BGO晶体内Po210等alpha放射性污染含量、探测器能量分辨、以及alpha v.s. beta/gamma粒子鉴别能力。
Femtoscopy is a powerful technique used to investigate the emission source and interaction potential between pairs of particles. The two-particle correlation function, which reveals valuable information about the space-time evolution of the emitting source and final state interaction, is the primary observable of interest. A detailed knowledge of hyperon-nucleon (Y-N) interaction is important...
Femtoscopic measurements are sensitive to the spatial and temporal characteristics of the particle emitting-source, allowing us to probe the properties of the matter created in heavy-ion collisions. In case of a first-order phase transition, the duration of pion emission is expected to increase. Therefore, measuring the energy dependence of the pion femtoscopy will help us to understand the...
We carry out a detailed study of medium modifications on momentum and angular correlations between a large transverse momentum hadron and a Z/γ trigger in relativistic heavy-ion collisions within a perturbative QCD parton model improved by the Sudakov resummation technique. The total energy loss of a hard parton propagating inside the medium is employed to modify the fragmentation function,...
WIMP是最热门的暗物质候选粒子之一，近年来国际上有多个大型深地探测实验致力于WIMP的直接探测，包括位于我国四川锦屏地下实验室的PandaX。PandaX-4T是基于吨量级的氙的两相型TPC探测器，其低阈值、低本底、大灵敏体积、高探测效率等特点，使之跻身于WIMP探测前列。本报告将介绍PandaX-4T实验在WIMP暗物质的搜寻中信号响应模型，讨论模型的构建以及应用。
This work presents a phenomenological study on the angle between the Standard and the Winner-Take-All (WTA) jet axes ($\Delta R$) in high-energy nuclear collisions. Our theoretical results calculated by the LBT model show that the $\Delta R$ distribution in Pb+Pb at $\sqrt{s}=5.02$ TeV is narrower than that in p+p, which agrees well with the recent ALICE measurements. The narrowing of $\Delta...
The directed flow in asymmetric collisions, such as Cu+Au, offers a valuable window into understanding the energy deposition mechanisms in heavy ion collisions, yet this remains an open challenge. In this work, we delve into the directed flow of charged hadrons in Cu+Au collisions at a center-of-mass energy of $\sqrt{s_{NN}}=200$ GeV. We develop a refined three-dimensional (3D) TRENTo initial...
Light nuclei are loosely bound objects with a few MeV binding energies. The systematic measurement of light nuclei production in heavy-ion collisions across a wide energy range is a valuable tool to probe the QCD phase structure and gain insight into the underlying production mechanism. In 2018, RHIC started the second phase of the beam energy scan program (BES-II). The STAR Fixed Target (FXT)...
The tau lepton is the heaviest known lepton with a relatively long lifetime and approximately 65% hadronically decays, including undetectable neutrinos, leaving characteristic displacement, multiplicity, and kinematic properties, making the reconstruction, identification, and calibration very challenging. But the final states with hadronically decaying tau leptons play an important part in the...
The next generation liquid xenon detector will have about ~50T liquid xenon, the new designed powerful cryogenics and purificaton will be introduced, the results of the prototype will be given.
The DarkSHINE experiment proposes a novel approach to single-electron-on-fixed-target exploration, focusing on the search for dark photons through its invisible decay to dark matter particles. Central to its design is the tracker detector, engineered to deliver exceptional sensitivity in detecting light dark matter candidates. Leveraging advancements in detector technology, particularly the...
In high-energy physics experiments, visualization software is essential for tasks such as detector design, offline data processing, and enhancing physics analysis. Detailed detector geometries and architectures, formatted in GDML or ROOT, are integrated into platforms like Unity for three-dimensional modeling. In this study, focusing on the BESIII spectrometer, Unity is used to display BESIII...
DD4hep是一个通用的探测器描述工具包，已被推荐用于下一代高能物理实验中的离线软件开发。FBX是一种流行的3D建模文件格式，广泛应用于工业3D建模与可视化软件中。我们研究了一种新方法，能够自动将复杂的高能物理探测器描述从DD4hep格式自动转化为FBX格式的3D建模文件。该方法经测试可用于紧凑型直线对撞机CLIC、超级陶粲装置STCF、环形正负电子对撞机CEPC等多个未来实验中基于DD4hep的探测器描述。自动的DD4hep-FBX探测器转换接口为下一代高能物理实验中的应用开发提供了便利，如探测器设计、模拟、可视化、数据监控和科普宣传等。
中子嬗变掺杂锗NTD-Ge是通过中子辐照及相应的嬗变掺杂过程产生具有十分均匀掺杂分布的锗半导体，在极低温度下其电阻对温度变化十分灵敏，且具有信号读出相对简单、大动态范围等独特优势，广泛应用于低温晶体量热器的热传感器。我们在中国先进研究堆对一批10N 纯度的高纯锗进行了热中子辐照，经过放射性冷却之后，对NTD-Ge的热中子辐照剂量、中子辐照缺陷以及载流子浓度等关键特性进行了测量研究。探索制定了NTD-Ge热传感器的电极制备流程，涉及表面抛光、离子注入、真空镀膜等多种微纳加工工艺，并解决了NTD-Ge金属电极粘附性差的问题。利用搭建的NTD-Ge极低温测试系统，对制备的NTD-Ge热传感器的极低温电阻-温度性能进行了测量，得到最低~20 mK低温下NTD-Ge的R-T特性符合理论预期的优良结果。
对手征磁场效应(Chiral Magnetic Effect, CME)的测量在近十年的高能核物理实验领域是一个热门方向。通常的实验手段包括寻找带电粒子及其来源的部分子(parton)由于受磁场影响而产生的各向异性运动，尤其是在相对于碰撞反应平面(Reaction Plane, RP)垂直方向。为此需要分离CME驱动的信号和作为相对背景的集体事件流(flow)尤其是其二阶部分即椭圆流(elliptic...
伴随着SiPM探测器在PET探测器发展中的应用越来越广泛，PET对读出电子学的小型化和低能耗提出了新的要求。我们提出了一个可以提供128通道的多极性电荷数字转换器(dQDC)的前端电子学方案。整个前端板包括模拟电路板和数字电路板，其中每一个通道仅包含模拟电路板中两个电阻，一个运算放大器，一个电容，数字电路板中一个电压输入和放电的两个FPGA I/O接口。数字电路板采用了一个低功耗的FPGA作为整个电子学的数据采集系统，使用SSTL...
正在我国进行建设的超级陶粲装置（STCF）中需要实现一种全新的、具有较好时间测量能力的电磁量能器（ECAL），以满足背景噪声抑制、中子-γ甄别等物理需求。对时间测量电子学的需求包括：不低于100-ps的分辨率、2-μs以上的动态范围以及可多通道集成。因此，我们提出了一种3级量化结构的时间数字转换器（TDC），其中粗量化由可达到较大动态范围的计数器实现；细量化则是基于一种改进的游标延迟环，利用两种延迟锁相环实现了亚门级延迟的高分辨率。所提出的游标延迟环采用了自动复位机制来实现连续事件的测量，还可利用滑动尺度测量原理显著提高其测量线性度。采用180-nm标准CMOS工艺实现了该TDC原型芯片，共集成了8个测量通道，在100-MHz参考时钟频率下可实现41.7-ps的分辨率和2.56-μs的动态范围。测试结果显示，该TDC的单射精度可达到46.0-ps，DNL不超过0.5-LSB，INL不...
为了提高LHC的物理研究潜力，LHC将升级为高亮度大型强子对撞机（HL-LHC），束流亮度的提高将使质子-质子碰撞的堆积度提高到约200。由于高亮度导致的辐射损伤，ATLAS探测器中内径迹探测器（ITk）的最内两层硅像素探测器将在积分亮度达到2000...
探测器描述是高能物理实验离线软件中的重要组成部分。Unity等专业的可视化平台拥有目前工业界最先进的可视化技术与软硬件支持，可以帮助实现复杂探测器的可视化，为实验中的探测器设计、模拟重建、事例显示等工作带来便利。本项工作重点在于开发一个通用的自动接口，能够高效地将高能物理实验离线软件中目前以GDML, DD4hep, ROOT, Geant4等格式描述的探测器自动转化为工业界流行的FBX格式，并在Unity等软件中导入从而实现探测器自动建模。该转化接口已成功应用于BESIII、JUNO、EicC、CEPC、STCF、CLIC等多个实验中不同类型的探测器描述，将其转换成FBX格式三维模型并导入到Unity中实现显示。该自动转化接口能够为现有和未来高能物理实验中的探测器设计、离线软件开发、物理分析乃至教育科普等起到辅助作用，同时也为事例显示、虚拟现实等进一步的可视化应用开发提供了良好的基础。
