核理论
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显示 2025年10月03日， 星期五 新的列表
- [1] arXiv:2510.01512 [中文pdf, pdf, html, 其他]
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标题： 非线性因果性和重子丰富Israel-Stewart流体力学的强双曲性标题： Nonlinear causality and strong hyperbolicity of baryon-rich Israel-Stewart hydrodynamics评论： 4页。将发表于《Quark Matter 2025》论文集主题： 核理论 (nucl-th) ; 高能天体物理现象 (astro-ph.HE) ; 广义相对论与量子宇宙学 (gr-qc)
我们提出了第一组完全非线性的必要且充分条件，确保带有剪切粘性和体积粘性并与非零重子流耦合的Israel-Stewart流体力学方程的初始数据的因果演化。 这些约束不仅提供非线性因果性：它们还（a）在排除边界端点时保证初始数据的局部良好 posed 演化（它们强制强双曲性），（b）来自于纯粹代数约束，这些约束对自由度没有做出任何潜在对称性假设，（c）在整个问题演化过程中传播自由度的相关对称性。 我们的工作为未来研究富含重子物质的粘性相对论流体力学，包括中子星合并和重离子碰撞提供了数学上严谨的基础。
We present the first set of fully-nonlinear, necessary and sufficient conditions guaranteeing causal evolution of the initial data for the Israel-Stewart hydrodynamic equations with shear and bulk viscosity coupled to a nonzero baryon current. These constraints not only provide nonlinear causality: they also (a) guarantee the existence of a locally well-posed evolution of the initial data (they enforce strong hyperbolicity) when excluding the endpoints of the bounds, (b) arise from purely algebraic constraints that make no underlying symmetry assumptions on the degrees of freedom and (c) propagate the relevant symmetries of the degrees of freedom over the entire evolution of the problem. Our work enforces a mathematically rigorous foundation for future studies of viscous relativistic hydrodynamics with baryon-rich matter including neutron star mergers and heavy-ion collisions.
- [2] arXiv:2510.01928 [中文pdf, pdf, html, 其他]
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标题： 伽莫夫壳模型对$^7$Li 中奇异点的描述标题： Gamow shell model description of exceptional point in $^7$Li主题： 核理论 (nucl-th)
我们报告了在耦合通道表示法（GSM-CC）中的伽莫夫壳模型中首次识别出一个异常点（EP）。在$^{7}$Li 的能谱中，发现$5/2^-$双重态存在一个 EP，其中两个状态在能量和宽度上合并，相位刚度消失，S 矩阵出现双极点。这些特征直接体现在可观测量上：弹性截面呈现出分裂峰结构，相移显示单个$2\pi$跳变。这项工作证明了 GSM-CC 提供了一个强大的框架来探索核中的 EP 现象及其实验特征。
We report the first identification of an exceptional point (EP) within the Gamow Shell Model in the Coupled Channels representation (GSM-CC). In the spectrum of $^{7}$Li, an EP is found for the $5/2^-$ doublet, where the two states coalesce in both energy and width, the phase rigidity vanishes, and the S-matrix develops a double pole. These features manifest directly in observables: the elastic cross section acquires a split-peak structure, and the phase shift shows a single $2\pi$ jump. This work demonstrates that GSM-CC provides a powerful framework to explore EP phenomena in nuclei and their experimental signatures.
- [3] arXiv:2510.02053 [中文pdf, pdf, html, 其他]
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标题： 夸克-强子相变的锐度和杂化星的性质标题： The sharpness of the quark-hadron transition and the properties of hybrid stars主题： 核理论 (nucl-th)
我们研究了介于强子物质和夸克物质之间的相变的尖锐程度对中子星各种性质的影响。 我们通过使用高斯函数将一个强子模型与一个夸克模型结合，构建了混合状态方程。 这种方法引入了一个由两个参数表征的平滑过渡：一个参数表示相对于一阶相变点的过压，另一个参数与混合区域在重子化学势中的扩展范围有关。 我们发现相变的尖锐程度显著影响状态方程，其偏差可达几十个$\text{MeV fm}^{-3}$，与具有尖锐一阶相变的状态方程不同。 声速表现出多种行为，包括急剧下降、显著峰值和振荡模式，这取决于尖锐度参数。 在恒星结构方面，虽然最大中子星质量基本上不受相变尖锐度的影响，但恒星半径可能会显著变化。 更平滑的过渡会导致对应于混合星的质量-半径曲线段向左移动（最多1公里）。 潮汐可变形性随着过渡的平滑而减小，尤其是对于高质星星体。 我们的结果非常普遍，不依赖于所采用的具体强子和夸克物质模型。 事实上，从夸克-强子面团相的微观模型中得出的混合状态方程和恒星特性表现出与上述相同的特性。
We investigate the effects of the sharpness of the phase transition between hadronic matter and quark matter on various properties of neutron stars. We construct hybrid equations of state by combining a hadronic model with a quark model using a Gaussian function. This approach introduces a smooth transition characterized by two parameters: one representing the overpressure relative to the first-order phase transition point, and the other related to the range over which the hybrid region extends in baryon chemical potential. We find that the sharpness of the phase transition significantly influences the equation of state, which can deviate by several tens of $\text{MeV fm}^{-3}$ from the one with a sharp first-order transition. The speed of sound exhibits diverse behaviors, including drastic drops, pronounced peaks, and oscillatory patterns, depending on the sharpness parameters. In terms of stellar structure, while the maximum neutron star mass remains largely unaffected by the sharpness of the phase transition, the stellar radii can vary significantly. Smoother transitions lead to a leftward shift (up to 1 km) of the mass-radius curve segment corresponding to hybrid stars. The tidal deformability decreases with smoother transitions, especially for higher-mass stars. Our results are quite general and do not qualitatively depend on the specific hadronic and quark matter models employed. In fact, the hybrid equation of state and stellar properties derived from microscopic models of quark-hadron pasta phases display the same behavior as described above.
- [4] arXiv:2510.02124 [中文pdf, pdf, html, 其他]
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标题： 核壳模型的量子模拟：连接理论与硬件限制标题： Quantum simulation of nuclear shell model: bridging theory and hardware limitations评论： 12页，11图主题： 核理论 (nucl-th)
在本工作中，我们引入了一种新的量子比特映射策略，用于将变分量子本征求解器（VQE）应用于核壳模型计算，其中每个斯莱特行列式（SD）被映射到一个量子比特，而不是将量子比特分配给单个单粒子态。虽然这种方法在某些情况下可能会增加所需的总量子比特数，但它能够构建更简单的量子电路，这些电路与当前的噪声中等规模量子（NISQ）设备更加兼容。我们将该方法应用于七个核素，包括四个锂同位素$^{(6-9)}$Li 从\textit{p}-壳，$^{18}$F 从\textit{sd}-壳，以及两个较重的核素（$^{210}$Po 和$^{210}$Pb）。我们在噪声模拟器（FakeFez 后端）和量子硬件（$ibm\_pittsburgh$）上运行表示它们基态的电路。 对于较重的原子核，我们展示了将$^{210}$Po 和$^{210}$Pb 分别模拟为 22- 和 29- 量子比特系统的可行性。 此外，我们通过两量子比特门折叠使用零噪声外推（ZNE）来减轻模拟和硬件执行结果中的误差。 校正后，最佳结果在所有研究的原子核中与壳模型预测的偏差小于 4%。 这种基于 SD 的量子比特映射在较轻的原子核和两核子系统中特别有效，为核物理中的近期量子模拟提供了一条有前景的途径。
In this work, we introduce a new qubit mapping strategy for the Variational Quantum Eigensolver (VQE) applied to nuclear shell model calculations, where each Slater determinant (SD) is mapped to a qubit, rather than assigning qubits to individual single-particle states. While this approach may increase the total number of qubits required in some cases, it enables the construction of simpler quantum circuits that are more compatible with current noisy intermediate-scale quantum (NISQ) devices. We apply this method to seven nuclei, including four lithium isotopes $^{(6-9)}$Li from \textit{p}-shell, $^{18}$F from \textit{sd}-shell, and two heavier nuclei ($^{210}$Po, and $^{210}$Pb). We run those circuits representing their g. s. on noisy simulator (FakeFez backend) and quantum hardware ($ibm\_pittsburgh$). For heavier nuclei, we demonstrate the feasibility of simulating $^{210}$Po and $^{210}$Pb as 22- and 29-qubit systems, respectively. Additionally, we employ Zero-Noise Extrapolation (ZNE) via two-qubit gate folding to mitigate errors in both simulated and hardware-executed results. Post-mitigation, the best results show less than 4 \% deviation from shell model predictions across all nuclei studied. This SD-based qubit mapping proves particularly effective for lighter nuclei and two-nucleon systems, offering a promising route for near-term quantum simulations in nuclear physics.
新提交 (展示 4 之 4 条目 )
- [5] arXiv:2510.01431 (交叉列表自 hep-ph) [中文pdf, pdf, html, 其他]
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标题： 强磁场中的强子物质不是好的强子共振气体模型标题： Hadron resonance gas is not a good model for hadronic matter in a strong magnetic fieldPasi Huovinen, Michał Marczenko, Michał Szymański, Bithika Karmakar, Pok Man Lo, Chihiro Sasaki, Krzysztof Redlich评论： 4页，3图，2025年夸克物质会议论文集主题： 高能物理 - 现象学 (hep-ph) ; 核理论 (nucl-th)
我们研究磁场对强子共振气体中粒子产率和电荷涨落的影响。 我们认为质子产率和重子数敏感度的显著变化是由于对高自旋态的描述不明确，而且由于详细平衡，中性共振态也必须受到磁场的影响。
We study the effect of magnetic field on particle yields and charge fluctuations in hadron resonance gas. We argue that the big changes in the proton yield and baryon number susceptibility are due to ill-defined description of higher-spin states, and that because of detailed balance, neutral resonances must be affected by the field too.
- [6] arXiv:2510.01505 (交叉列表自 hep-ph) [中文pdf, pdf, html, 其他]
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标题： 带有多个奇异夸克的单重重四夸克共振态标题： Singly heavy tetraquark resonant states with multiple strange quarks评论： 10页，4图，5表，欢迎提出意见主题： 高能物理 - 现象学 (hep-ph) ; 高能物理 - 实验 (hep-ex) ; 高能物理 - 格点 (hep-lat) ; 核理论 (nucl-th)
我们系统地研究了包含两个或三个奇异夸克的S波单重重四夸克系统，即$Qs\bar{s}\bar{s}$、$Qn\bar{s}\bar{s}$和$Qs\bar{s}\bar{n}\left( Q=c,b,n=u,d \right) $，在组成夸克势模型中。 我们使用高斯展开方法（GEM）求解四体薛定谔方程，并通过复数缩放方法（CSM）识别共振态。 在最低的两介子阈值以下没有束缚态。 我们获得了在$Qs\bar{s}\bar{s}$中的$J^P=0^+,2^+$以及在$Qn\bar{s}\bar{s}$和$Qs\bar{s}\bar{n}$中的$J^P=2^+$的几个紧凑共振。 极点位置主要分布在$7.0-7.2$GeV（底部）和$3.7-3.9$GeV（魅）附近，宽度从几到几十 MeV。 这些共振衰变为$D_s\eta ^\prime ,{D_{(s)}^*}\phi ,{D_s}^*K^*$和$D_s^*\bar{K}^*$（以及它们的底夸克对应态），为未来的实验搜索提供了目标。
We systematically investigate the S-wave singly heavy tetraquark systems containing two or three strange quarks, $Qs\bar{s}\bar{s}$, $Qn\bar{s}\bar{s}$ and $Qs\bar{s}\bar{n}\left( Q=c,b,n=u,d \right) $, within the constituent quark potential model. We solve the four-body Schr\"odinger equation using the Gaussian expansion method (GEM) and identify resonances via the complex scaling method (CSM). There are no bound states below the lowest two-meson thresholds. We obtain several compact resonances with $J^P=0^+,2^+$ in $Qs\bar{s}\bar{s}$, and $J^P=2^+$ in $Qn\bar{s}\bar{s}$ and $Qs\bar{s}\bar{n}$. The pole positions are mainly distributed around $7.0-7.2$ GeV (bottom) and $3.7-3.9$ GeV (charm), with widths from a few to several tens of MeV. These resonances decay into $D_s\eta ^\prime ,{D_{(s)}^*}\phi ,{D_s}^*K^*$ and $D_s^*\bar{K}^*$ (and their bottom counterparts), providing targets for future experimental searches.
- [7] arXiv:2510.01822 (交叉列表自 hep-ph) [中文pdf, pdf, html, 其他]
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标题： 高多重性碰撞事件中的粒子动量谱、关联性和最大熵原理标题： Particle momentum spectra, correlations, and maximum entropy principle in high-multiplicity collision events评论： 16页主题： 高能物理 - 现象学 (hep-ph) ; 高能物理 - 理论 (hep-th) ; 核理论 (nucl-th)
在本文中，我们利用最大熵原理来确定小碰撞系统在动能冻结时刻的量子态。 我们通过对此态施加固定的粒子数约束，推导出多粒子选择的粒子动量谱和关联函数的表达式。 我们分析的结果可能有助于解释固定LHC能量下高多粒子$pp$碰撞事件中粒子动量谱和关联的多粒子依赖性。
In this paper, we utilize the maximum entropy prescription to determine a quantum state of a small collision system at the kinetic freeze-out. We derive expressions for multiplicity-selected particle momentum spectra and correlation functions by applying a fixed particle number constraint to this state. The results of our analysis may be useful for interpreting the multiplicity dependence of the particle momentum spectra and correlations in high-multiplicity $pp$ collision events at a fixed LHC energy.
- [8] arXiv:2510.01962 (交叉列表自 hep-ph) [中文pdf, pdf, html, 其他]
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标题： 色散关系：基础标题： Dispersion relations: foundations评论： 15页，4图；对粒子物理百科全书的贡献主题： 高能物理 - 现象学 (hep-ph) ; 核理论 (nucl-th)
我们提供一个教学性的介绍，阐述粒子物理中色散关系的基本思想。 从基本的机械系统出发，我们展示因果性这一物理原理如何与解析性这一数学性质密切相关，并且如何在量子力学散射理论中得到实现。 我们选取了一些个人认为基础的应用，例如强子产生振幅或形式因子与散射之间的关系，以及在非物理黎曼面上提取共振特性。 还简要涉及了一些更高级的主题，如π-π散射的Roy方程以及三体衰变的色散关系。
We give a pedagogical introduction to the founding ideas of dispersion relations in particle physics. Starting from elementary mechanical systems, we show how the physical principle of causality is closely related to the mathematical property of analyticity, and how both are implemented in quantum mechanical scattering theory. We present a personal selection of elementary applications such as the relation between hadronic production amplitudes or form factors to scattering, and the extraction of resonance properties on unphysical Riemann sheets. More advanced topics such as Roy equations for pion--pion scattering and dispersion relations for three-body decays are briefly touched upon.
- [9] arXiv:2510.02076 (交叉列表自 hep-ph) [中文pdf, pdf, html, 其他]
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标题： 轻夸克S波五夸克在轻子面上标题： Light S-wave pentaquarks on the light front评论： 14页，4图主题： 高能物理 - 现象学 (hep-ph) ; 核理论 (nucl-th)
我们构建了一个在规则4-单形上用于五夸克态的显式基集，该基集对角化了轻五夸克在轻子前面上的哈密顿量。由此得到的本征态不受质心运动的影响，并满足精确的狄利克雷边界条件。以颜色自旋或味自旋形式的超精细相互作用被证明可以消除16个五夸克态的简并性，其能谱与一些经验核子激发态相当。讨论了轻五夸克态的夸克PDF。
We construct an explicit basis set for pentaquark states on a regular 4-simplex, that diagonalizes the Hamiltonian for light pentaquarks with confinement on the light front (LF). The ensuing eigenstates are free of the center of mass motion and satisfy exact Dirichlet boundary conditions. Hyperfine interactions in the form of color-spin or flavor-spin are shown to lift the degeneracy of the 16 pentastates, with a spectrum that compares fairly with some of the empirical nucleon excited states. The quark PDF for the light pentastates is discussed.
- [10] arXiv:2510.02254 (交叉列表自 hep-ph) [中文pdf, pdf, html, 其他]
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标题： 部分子分布在冲击波形式中标题： Parton distributions in the shockwave formalism评论： 49页，11图主题： 高能物理 - 现象学 (hep-ph) ; 核理论 (nucl-th)
在本工作中，我们直接从靶核子的冲击波近似下的算符级定义计算了一大类部分子分布——包括部分子分布函数（PDFs）、与横动量相关的分布（TMDs）、广义部分子分布（GPDs）、广义与横动量相关的分布（GTMDs）以及衍射部分子分布。 此近似在散射的高能极限下有效，对应于小-$x$的区域。 冲击波框架使我们能够采用eikonal近似，并将部分子分布表示为威尔逊线相关函数，在颜色玻璃凝聚有效场理论中自然表述。 我们提出了在该极限下评估部分子分布的一整套费曼规则，并展示了如何系统地应用它们来计算所有在领先阶下具有物理意义的领先扭度部分子分布。 本工作为未来旨在将颜色玻璃凝聚方法与核子的粒子描述相衔接的研究建立了一个统一的起点。
In this work, we calculate a broad class of parton distributions - including parton distribution functions (PDFs), transverse-momentum-dependent distributions (TMDs), generalized parton distributions (GPDs), generalized transverse-momentum-dependent distributions (GTMDs), and diffractive parton distributions - directly from their operator-level definition in the shockwave approximation for the target nucleon. This approximation is valid in the high-energy limit of scattering, corresponding to the small-$x$ regime. The shockwave framework allows us to employ the eikonal approximation and express the parton distributions in terms of Wilson-line correlators, naturally formulated within the color-glass condensate effective field theory. We present a comprehensive set of Feynman rules for evaluating parton distributions in this limit, and demonstrate how they can be systematically applied to calculate all phenomenologically relevant leading-twist parton distributions at leading order. This work establishes a unified starting point for future studies that aim to bridge the color-glass condensate approach with the partonic description of the nucleon.
交叉提交 (展示 6 之 6 条目 )
- [11] arXiv:2404.09780 (替换) [中文pdf, pdf, html, 其他]
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标题： $^{16}$O与$^{16}$O碰撞在顶级RHIC能量下的核团结构效应标题： Nuclear cluster structure effect in $^{16}$O+$^{16}$O collisions at the top RHIC energy评论： 已采用改进的AMPT-SM模型，详细内容见新的附录主题： 核理论 (nucl-th) ; 高能物理 - 现象学 (hep-ph)
使用改进的AMPT-SM模型，我们研究了$^{16}$O的核几何结构对在$\sqrt{s_{_{\mathrm{NN}}}}=200$GeV下O+O碰撞中各向异性流的影响。为了评估核结构和势α团簇的影响，我们实现了四种候选配置：Woods-Saxon、四面体、正方形和NLEFT。初始状态的几何结构通过偏心率累积比$\varepsilon_{2}\{4\}/\varepsilon_{2}\{2\}$来量化，该比值提供了一个稳健且与演化无关的测量方法，对配置差异敏感。 模型在低$p_{\mathrm{T}}$时再现$v_{2}(p_{\mathrm{T}})$，并在整个$p_{\mathrm{T}}$范围内再现$v_{3}(p_{\mathrm{T}})$，积分$v_{2}\{2\}$和$v_{3}\{2\}$与 STAR 数据匹配，证明输运动力学捕捉了这一中等尺寸系统中的基本集体性。 这些发现建立了一个基准，以便在统一的输运模型框架内将 O+O 碰撞中的核结构研究扩展到其他能量和微分可观测量。
Using the improved AMPT-SM model, we investigated the impact of nuclear geometry of $^{16}$O on anisotropic flows in O+O collisions at $\sqrt{s_{_{\mathrm{NN}}}}=200$ GeV. To evaluate the influence of nuclear structure and potential alpha clustering, we implemented four candidate configurations: Woods-Saxon, tetrahedron, square, and NLEFT. Initial-state geometry is quantified via the eccentricity cumulant ratio $\varepsilon_{2}\{4\}/\varepsilon_{2}\{2\}$, which provides a robust and evolution-independent measure sensitive to configuration differences. The model reproduces $v_{2}(p_{\mathrm{T}})$ at low $p_{\mathrm{T}}$ and $v_{3}(p_{\mathrm{T}})$ across the full $p_{\mathrm{T}}$ range, with integrated $v_{2}\{2\}$ and $v_{3}\{2\}$ matching the STAR data, demonstrating that transport dynamics captures the essential collectivity in this intermediate-size system. These findings establish a baseline for extending nuclear-structure studies in O+O collisions to other energies and differential observables within a unified transport model framework.
- [12] arXiv:2412.18118 (替换) [中文pdf, pdf, html, 其他]
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标题： 质子螺旋性引起的$(\vec{p},2p)$反应中的手性标题： Chirality in $(\vec{p},2p)$ reactions induced by proton helicity主题： 核理论 (nucl-th) ; 核实验 (nucl-ex)
结果显示，当最终态存在三个动量矢量不共面的粒子时，在中等能量下，纵向极化的质子可以用来在$(\vec{p},pN)$反应的最终态中诱导手性。提出分析能力$A_z$作为衡量此效应的指标。给出了基于直观图像以及变形波冲击近似的理论描述，以获得$A_z$，表明入射质子的螺旋度与单粒子波函数轨道运动的手性耦合，导致最终态的手性和较大的$A_z$值。
It is shown that longitudinally-polarized protons can be used to induce chirality in final states of the $(\vec{p},pN)$ reaction at intermediate energies, when there exist three final-state particles with non-coplanar momentum vectors. The analyzing power $A_z$ is proposed as a measure of this effect. Theoretical descriptions to obtain $A_z$ based on an intuitive picture as well as a distorted wave impulse approximation are presented, showing that the helicity of incident protons is coupled to the chirality of the orbital motion of a single-particle wave function, resulting in the chirality of the final states and a large $A_z$ value.
- [13] arXiv:2503.04015 (替换) [中文pdf, pdf, html, 其他]
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标题： 在手征孤子模型中空间非均匀场背景上的量子涨落能标题： Quantum fluctuation energies over a spatially inhomogeneous field background in a chiral soliton model评论： 23页，8图主题： 核理论 (nucl-th)
基于手征孤子模型，对在空间非均匀介子场背景上夸克的量子涨落能量进行了深入研究。 我们采用由施温格发起的系统计算方案，在该方案中，环状量子涨落能量通过有效哈密顿量本征值谱上的非平凡能级求和来评估。 有效哈密顿量可以通过在静态手征孤子场背景上夸克涨落的一圈有效作用量来构建。 得到了相应的狄拉克方程。 在静态且空间球对称的情况下，并通过刺猬假设，可以将狄拉克方程波函数的整体自旋的径向部分和角部分分离。 由于孤子背景的存在，本征值谱被扭曲。 可以通过求解不同动量下的径向方程来确定散射相移。 可以推导出动量空间中的态密度。 有效哈密顿量在一个由宇称、整体自旋和能量标记本征函数的希尔伯特空间中被对角化。 可以通过相移的玻恩减法和补偿费曼图重整化来执行重整化方案。 最后，数值计算、比较和讨论了在不同宇称和整体自旋下，手征孤子背景上的有限量子涨落能量。
Based on chiral soliton models, the quantum fluctuation energies of quarks over a spatially inhomogeneous meson field background have been thoroughly studied. We have used a systematic calculation scheme initiated by Schwinger, in which the loop quantum fluctuation energies are evaluated by a nontrivial level summation over the eigenvalue spectrum of the effective Hamiltonian of the system. The effective Hamiltonian can be constructed by one loop effective action of fluctuations of quarks over a static chiral soliton field background. The corresponding Dirac equation is obtained. In a static and spatially spherical case and by the hedgehog ansatz the radial part and the angular part of the grand spin of the wave function for the Dirac equation can be separated. Due to the soliton background the eigenvalue spectrum are distorted. The scattering phase shift can be determined by solve the radial equations at different momentum. The density of states in momentum space can be derived. The effective Hamiltonian has been diagonalized in a Hilbert space where the eigenfunctions are labeled by the parity, grand spin and energy. The renormalization scheme can be carried out by a Born subtraction of the phase shift and the compensating Feynman diagram renormalization. Finally the finite quantum fluctuation energies over chiral soliton background at different parities and grand spins have been numerically evaluated, compared and discussed.
- [14] arXiv:2506.05849 (替换) [中文pdf, pdf, html, 其他]
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标题： 相对论碰撞中独特核结构的费米洛斯特征标题： Femtoscopic signatures of unique nuclear structures in relativistic collisions评论： 8页，5图主题： 核理论 (nucl-th) ; 高能物理 - 现象学 (hep-ph)
当今高能核物理中最关键的研究课题之一是碰撞核的核结构研究。 在相对论重离子对撞机（RHIC）和大型强子对撞机（LHC）上的最新研究显示，诸如产生的粒子集体流和横向动量相关性等可观测量可以对各种核结构和形变参数敏感。 飞秒显微技术，另一种用于研究核碰撞中产生物质时空几何结构的重要工具，尚未被广泛应用于此类研究。 在本文中，使用多相输运模型（AMPT），证明了介子对的飞秒显微源参数也可以作为独特核结构的稳健信号。 通过对 $^{208}$Pb+$^{20}$Ne 和 $^{208}$Pb+$^{16}$O 碰撞在 $\sqrt{s_{NN}}$ = 68.5 GeV 下的分析，两个与LHCb实验的SMOG2计划特别相关的碰撞系统，结果表明，变形的初始形状可以显著影响飞秒显微源参数。 这项研究强调了将核结构研究扩展到飞秒显微可观测量的重要性，并为此新方向的众多可能未来研究提供了一个基准。
One of the most vital topics of today's high-energy nuclear physics is the investigation of the nuclear structure of the collided nuclei. Recent studies at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC) have shown that several observables, such as the collective flow and transverse-momentum correlations of the produced particles, can be sensitive to various nuclear structure and deformation parameters. Femtoscopy, another essential tool for investigating the space-time geometry of the matter created in nuclear collisions, has not yet been widely applied to such studies. Using a multiphase transport model (AMPT), in this Letter, it is demonstrated that the femtoscopic source parameters of pion pairs can also serve as a robust signal of unique nuclear structure. Through an analysis of $^{208}$Pb+$^{20}$Ne and $^{208}$Pb+$^{16}$O collisions at $\sqrt{s_{NN}}$ = 68.5 GeV, two collision systems especially relevant to the SMOG2 program of the LHCb experiment, it is shown that a deformed initial shape can significantly affect femtoscopic source parameters. This study highlights the importance of expanding the nuclear structure investigations to femtoscopic observables and serves as a baseline for numerous possible future studies in this new direction.
- [15] arXiv:2506.13944 (替换) [中文pdf, pdf, html, 其他]
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标题： RHIC BES能量下综合流体力学模型中的粒子谱标题： Particle Spectra in the Integrated HydroKinetic Model at RHIC BES Energies评论： 11页，5图主题： 核理论 (nucl-th) ; 高能物理 - 现象学 (hep-ph)
我们使用扩展的集成流体力学模型（iHKMe）研究在$\sqrt{s_{NN}} = 7.7-39$ GeV 下金-金碰撞中的轻强子产生。 聚焦于横向动量谱，我们研究了对关键模型参数的敏感性，特别是热化时间尺度。 我们考虑两种不同的状态方程：一种具有交叉相变，另一种具有第一阶相变。 在两种情况下，热化在完全核重叠之前不久开始，并且在所有能量下持续约 1~fm/$c$。 一旦其他参数稍作调整，两种状态方程都能同样好地描述软粒子动量谱。 最显著的差异出现在 RHIC BES 能量较低的$\sqrt{s_{NN}} = 7.7$ GeV 处，特别是在质子和K介子产率方面，这反映了它们对冻结参数的敏感性。
We study light-hadron production in Au+Au collisions at $\sqrt{s_{NN}} = 7.7-39$ GeV using an extended Integrated HydroKinetic Model (iHKMe). Focusing on transverse momentum spectra, we investigate the sensitivity to key model parameters, in particular the thermalization time scale. We consider two distinct equations of state: one featuring a crossover and the other a first-order phase transition. In both cases, thermalization begins shortly before full nuclear overlap and lasts approximately 1~fm/$c$ across all energies. Both equations of state provide a similarly good description of the soft particle momentum spectra once the other parameters are slightly adjusted. The most pronounced differences arise at the lower RHIC BES energy of $\sqrt{s_{NN}} = 7.7$ GeV, particularly in proton and kaon yields, reflecting their sensitivity to the freeze-out parameters.
- [16] arXiv:2509.14301 (替换) [中文pdf, pdf, html, 其他]
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标题： 一种改进的Wigner函数和自旋极化公式在局部热平衡的解耦相对论流体中标题： An improved formula for Wigner function and spin polarization in a decoupling relativistic fluid at local thermodynamic equilibrium评论： 14页，1图主题： 核理论 (nucl-th) ; 高能物理 - 现象学 (hep-ph) ; 高能物理 - 理论 (hep-th)
我们提出了一种改进的Wigner函数和费米子在退耦时由相对论流体在局部热平衡下发射的自旋极化公式，该公式优于参考文献[1, 2]中得到的公式，并用于相对论核碰撞的数值模拟。通过使用一种新的展开方法，适用于任意几何结构的退耦超曲面，我们重现了与热涡度成比例的已知项，并得到了一个改进的自旋-剪切项，该术语捕捉了几何依赖性。新方法还包括一些额外贡献，其物理性质有待评估。新表达式自然排除了超曲面法向方向上的时空梯度贡献，为之前先验施加的等温条件提供了理论依据。此框架可以扩展到任意自旋的粒子。
We present an upgraded formula for Wigner function and spin polarization of fermions emitted by a relativistic fluid at local thermodynamic equilibrium at the decoupling which improves the one obtained in refs. [1, 2] and used in numerical simulations of relativistic nuclear collisions. By using a new expansion method, applicable to decoupling hypersurfaces with arbitrary geometry, we reproduce the known term proportional to thermal vorticity and obtain an upgraded form of the spin-shear term which captures the dependence on the geometry. The new method also includes additional contributions whose physical nature is to be assessed. The new expression also naturally excludes contributions from space-time gradients in the normal direction of the hypersurface, providing a theoretical justification for the isothermal condition previously imposed a priori. This framework can be extended to particles with arbitrary spin.
- [17] arXiv:2303.08143 (替换) [中文pdf, pdf, 其他]
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标题： 用能量关联函数探测冷核物质标题： Probing cold nuclear matter with energy correlators评论： 11页，11幅精美图示，以及附录期刊参考： 物理评论C 112，035202（2025）主题： 高能物理 - 现象学 (hep-ph) ; 高能物理 - 实验 (hep-ex) ; 核实验 (nucl-ex) ; 核理论 (nucl-th)
未来电子-离子碰撞器（EIC）将产生电子与各种核的首次高能碰撞，开启研究冷核物质的新时代。 在这些碰撞中产生的夸克和胶子将在核的致密物质中传播，将其结构刻入最终态强子能量通量的细微关联中。 在本文中，我们将喷注子结构领域最近的发展，即能量关联观测量，应用于解码这些关联，并提供一种观察核结构的新窗口。 能量关联量提供了对真空量子色动力学（QCD）尺度依赖性的校准探测，使介质修改能够作为尺度的函数被成像和解释。 使用eHIJING部分子簇射模拟电子-核碰撞，我们证明了核的大小在关联量中以角度尺度体现，其大小在现实的EIC动量条件下是可见的。 我们可以观察到所提议的EIC核靶之间的大小差异${}^3$He, ${}^4$He, ${}^{12}$C, ${}^{40}$Ca, ${}^{64}$Cu, ${}^{197}$Au, 和 ${}^{238}$U，表明能量关联量可以利用渐近能量通量成像飞米长度尺度。 我们的方法为对撞机实验中的喷注子结构提供了统一的观点，并提供了许多新的理论工具，以揭示极端环境中（无论是热还是冷）QCD的复杂动力学。
The future electron-ion collider (EIC) will produce the first-ever high energy collisions between electrons and a wide range of nuclei, opening a new era in the study of cold nuclear matter. Quarks and gluons produced in these collisions will propagate through the dense nuclear matter of nuclei, imprinting its structure into subtle correlations in the energy flux of final state hadrons. In this article, we apply recent developments from the field of jet substructure, namely the energy correlator observables, to decode these correlations and provide a new window into nuclear structure. The energy correlators provide a calibrated probe of the scale dependence of vacuum quantum chromodynamics (QCD), enabling medium modifications to be imaged and interpreted as a function of scale. Using the eHIJING parton shower to simulate electron-nucleus collisions, we demonstrate that the size of the nucleus is imprinted as an angular scale in the correlators, with a magnitude that is visible for realistic EIC kinematics. We can observe the size difference between the proposed EIC nuclear targets ${}^3$He, ${}^4$He, ${}^{12}$C, ${}^{40}$Ca, ${}^{64}$Cu, ${}^{197}$Au, and ${}^{238}$U, showing that the energy correlators can image femtometer length scales using asymptotic energy flux. Our approach offers a unified view of jet substructure across collider experiments, and provides numerous new theoretical tools to unravel the complex dynamics of QCD in extreme environments, both hot and cold.
- [18] arXiv:2501.09738 (替换) [中文pdf, pdf, html, 其他]
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标题： 部分子分布函数和幅值使用张量网络方法标题： Partonic distribution functions and amplitudes using tensor network methods评论： 21页，4图，2表期刊参考： JHEP 09 (2025) 176主题： 高能物理 - 现象学 (hep-ph) ; 高能物理 - 格点 (hep-lat) ; 核理论 (nucl-th) ; 量子物理 (quant-ph)
部分子分布函数（PDF）和分布幅度（DA）的计算对于核心实验计划非常重要，因为它们分别提供了包括和排除过程的非微扰输入。 PDFs 和 DAs 的直接计算仍然具有挑战性，因为它们是非微扰量，定义为夸克和胶子场的光锥关联函数，因此本质上是时间依赖的。 在本工作中，我们使用基于张量网络模拟技术的统一量子策略，直接从第一原理提取这些强子量，使用相同设置下的强子矩阵乘积状态。 我们展示了在 1+1 维下使用 Nambu-Jona-Lasinio 模型的示例数值计算，并与现有的精确对角化和量子电路模拟结果进行比较。 利用张量网络，我们在大量子位极限下评估了不同强耦合下的 PDF 和 DA，这与微扰和非相对论极限下的预期一致。
Calculations of the parton distribution function (PDF) and distribution amplitude (DA) are highly relevant to core experimental programs as they provide non-perturbative inputs to inclusive and exclusive processes, respectively. Direct computation of the PDFs and DAs remains challenging because they are non-perturbative quantities defined as light-cone correlators of quark and gluon fields, and are therefore inherently time-dependent. In this work, we use a uniform quantum strategy based on tensor network simulation techniques to directly extract these hadronic quantities from first principles using the matrix product state of the hadrons in the same setup. We present exemplary numerical calculations with the Nambu-Jona-Lasinio model in 1+1 dimensions and compare with available exact diagonalization and quantum circuit simulation results. Using tensor networks, we evaluate the PDF and DA at various strong couplings in the large-qubit limit, which is consistent with expectations at perturbative and non-relativistic limits.
- [19] arXiv:2506.13555 (替换) [中文pdf, pdf, html, 其他]
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标题： 反应堆和加速器CE$ν$NS数据对锗的联合分析：对标准模型和核物理的意义标题： Joint analysis of reactor and accelerator CE$ν$NS data on germanium: implications for the Standard Model and nuclear physics评论： 10页，7图。符合已发表版本期刊参考： 物理评论快报 869 (2025) 139856主题： 高能物理 - 现象学 (hep-ph) ; 高能物理 - 实验 (hep-ex) ; 核理论 (nucl-th)
本工作首次对所有可用的相干弹性中微子-核散射（CE$\nu$NS）数据进行了全面联合分析，这些数据是在散裂中子源（SNS）由COHERENT合作组观测到的锗数据，以及由CONUS+实验使用锗探测器在核反应堆中揭示的数据。 除了COHERENT和CONUS+之外，我们还纳入了TEXONO和$\nu$GeN的反应堆数据，从而增强了研究的统计显著性和系统可靠性。 我们提供了关键核物理和标准模型参数的最新确定值，包括锗核的中子均方根（rms）半径、弱混合角以及中微子电荷半径。 观察到的约$2 \sigma$的COHERENT锗测量与标准模型预测之间的张力，促使我们对理论截面进行详细重新评估。 特别是，我们研究了核形式因子和核半径不确定性的影响力，以及SNS中中微子通量归一化可能的系统偏移的影响。 我们的结果强调了CE$\nu$NS作为精密工具的可靠性，这得到了不同实验输入互补性的支持，并为该领域的未来进展奠定了基础。
This work presents the first comprehensive joint analysis of all available Coherent Elastic Neutrino-Nucleus Scattering (CE$\nu$NS) data on germanium: those observed at the Spallation Neutron Source (SNS) by the COHERENT collaboration and those of the nuclear reactors revealed by the CONUS+ experiment using germanium detectors. In addition to COHERENT and CONUS+, we incorporate reactor data from TEXONO and $\nu$GeN, thereby enhancing both the statistical significance and the systematic reliability of our study. We provide state-of-the-art determinations of key nuclear physics and Standard Model parameters, including the neutron root-mean-square (rms) radius of germanium nuclei, the weak mixing angle, and the neutrino charge radius. The observed tension of about $2 \sigma$ between the COHERENT germanium measurement and the Standard Model prediction motivates a detailed reassessment of the theoretical cross-section. In particular, we examine the impact of nuclear form factors and uncertainties in the nuclear radius, as well as the potential influence of a systematic shift in the neutrino flux normalisation at the SNS. Our results highlight the reliability of CE$\nu$NS as a precision tool, reinforced by the complementarity of different experimental inputs, and lay the groundwork for future advances in the field.