分类： 核科学技术 >> 核科学与技术 分类： 物理学 >> 基本粒子与场物理学 提交时间： 2025-04-10
摘要： The precise measurement of the antineutrino spectra produced by isotope fission in reactors is of great significance for studying neutrino oscillations, refining nuclear databases, and addressing the reactor antineutrino anomaly. In this paper, we report a method that utilizes a feedforward neural network (FNN) model to decompose the prompt energy spectrum observed in a short-baseline reactor neutrino experiment and extract the antineutrino spectra produced by the fission of major isotopes such as235U,238U,239Pu, and241Pu in the nuclear reactor. We present two training strategies for the model and compare them with the traditionalχ2minimization method by applying them to the same set of pseudo-data corresponding to a total exposure of(2.9×5×1800)GWth⋅tonnes⋅days. The results show that the FNN model not only converges faster and better during the fitting process but also achieves relative errors of less than 1\% in the2−8MeV range in the extracted spectra, outperforming theχ2minimization method. The feasibility and superiority of this method were validated in the study.
分类： 物理学 >> 基本粒子与场物理学 分类： 物理学 >> 凝聚态:电子结构、电、磁和光学性质 分类： 电子与通信技术 >> 电子技术 分类： 物理学 >> 电磁学、光学、声学、传热、经典力学和流体动力学 提交时间： 2025-03-29
摘要： The self-force and the self-energy (Coulomb-velocity energy) of an electron moving along a rectilinear trajectory in the vacuum is analyzed numerically. It is illustrated for the first time that when the velocity of the electron approaches the light velocity in the vacuum, the Coulomb-velocity energy approaches infinitely large, so is the self-force. Consequently, electrons cannot be accelerated to move faster than the light in the vacuum using electric accelerators because infinite large external force may be required to make the electron cross the electromagnetic barrier of the light velocity in the vacuum. Based on the observation, the Bertozzi experiment is re-interpreted, which shows that the velocity limit is due to the intrinsic behavior of the electron that can be clearly explained with the classical Maxwell’s theory. It is obviously not so definite that this behavior of the electron is due to the effect of special relativity as claimed in text books. Therefore, the outcome of the Bertozzi experiment may be not an unquestionable experimental support to the Einstein’s theory of special relativity. It is natural to consider that neutral particles may move faster than the light velocity in the vacuum because they do not face the big electromagnetic self-force when they cross the electromagnetic barrier. Furthermore, a reasonable hypothesis can be made that superluminal electrons may be generated by the collision of high energy particles in a collider or in the universe.
分类： 物理学 >> 基本粒子与场物理学 提交时间： 2025-03-27
摘要： We investigate the influence of quark anomalous magnetic moments (AMM) on the mass spectra of neutral pseudoscalar mesons ($\pi$, $K$, $\eta$, $\eta^{’}$) under external magnetic fields, finite temperatures, and quark chemical potentials using the three-flavor Nambu-Jona-Lasinio (NJL) model. By incorporating AMM at the quark level, we reveal that AMM significantly alters the magnetic field dependence of constituent quark masses, inducing first-order phase transitions for light quarks at critical fields, while strange quarks exhibit non-monotonic mass behavior. The inclusion of AMM reshapes the QCD phase diagram, suppressing chiral transition temperatures and shifting critical endpoints (CEP) toward lower $\mu$ and $T$. Notably, crossover transitions observed without AMM are replaced by first-order transitions under strong fields, aligning with lattice QCD predictions for IMC. For mesons, AMM triggers abrupt mass collapses and enhances flavor mixing, accelerating chiral restoration for $K$ and $\eta$ mesons via thresholds tied to strange quark masses. The $\eta^{’}$ meson, as a resonance state, shows suppressed mass growth and instability at strong fields, highlighting limitations in handling non-perturbative decay widths within the NJL framework. These findings underscore AMM critical role in reconciling effective model predictions with LQCD results, particularly in explaining IMC and phase transition dynamics.
分类： 物理学 >> 基本粒子与场物理学 提交时间： 2025-02-20
摘要： We demonstrate that the propagator, derived from an Effective Field Theory (EFT) that incorporates Weinberger’s compositeness theorem, provides a more general formula for describing S-wave near-threshold states. By fitting the lineshape using this propagator, we can extract the $Z$ factor for these states and elucidate their structures.
分类： 物理学 >> 基本粒子与场物理学 提交时间： 2025-02-20
摘要： The purpose of this letter is to point out that some conclusions in the paper (Eur. Phys. J. C { bf 76}, 324(2016)) are incomplete, and to give complete and improved conclusions. The analytic necessary and sufficient conditions are given for the boundedness-from-below conditions of general scalar potentials of two real scalar fields $ phi_1$ and $ phi_2$ and the Higgs bonson $ mathbf{H}$.
分类： 物理学 >> 基本粒子与场物理学 提交时间： 2025-02-08
摘要： 本文考虑一种量子化的参考系理论，考虑这种时空参考系在量子二阶矩涨落下的Ricci流理论及其蕴含的引力理论。由于该理论中非平凡的时空二阶量子涨落，我们讨论了宇宙加速膨胀(宇宙学常数)问题、星系尺度的径向加速度反常问题，极早期暴涨等问题，及其时空熵的起源问题。最后我们也给出该理论的一些可能预言。
分类： 物理学 >> 基本粒子与场物理学 提交时间： 2025-02-03
摘要： This note aims to give a self-contain and detail explaination about U(k′)×U(k) Pati-Salam model in curved space-time which derived from (1 + n)-dimensional square root Lorentz manifold by self-parallel transportation principle. The concepts fundation of manifold from view point of category theory, fiber bundle and sheaf theories are reviewed. There are extra U(k′)×U(k)-principal bundle and U(k)- associated bundle than (1 + n)-dimensional Lorentz manifold. The conservative currents on square root Lorentz manifold is discussed preliminary. A detail proof of relation from sheaf quantization to path integral quantization is given.
分类： 物理学 >> 基本粒子与场物理学 分类： 核科学技术 >> 核科学与技术 提交时间： 2025-01-09
摘要： In this study, we conducted a comprehensive characterization and optimization of a cryogenic pure CsI (pCsI) detector. We utilized a \SI{2}{\centi\metre} cubic crystal coupled with a HAMAMATSU R11065 photomultiplier tube (PMT), achieving a remarkable light yield of \SI{35.2}{PE/\keV_{ee}} and an unprecedented energy resolution of \SI{6.9}{\%} at \SI{60}{\keV}. Additionally, we measured the scintillation decay time of pCsI, which proved to be significantly faster than that of CsI(Na) at room temperature. Furthermore, we investigated the impact of temperature, surface treatment, and crystal shape on the light yield. Notably, the light yield peaked at approximately \SI{20}{\K} and remained stable within the range of \SI{70}-\SI{100}{\K}. We observed that the light yield of polished crystals was approximately 1.5 times greater than that of ground crystals, while the crystal shape exhibited minimal influence on the light yield. These results are crucial for the design of the \SI{10}{\kg} pCsI detector for the future CLOVERS (Coherent eLastic neutrinO(V)-nucleus scattERing at China Spallation Neutron Source (CSNS)) experiment.
分类： 物理学 >> 基本粒子与场物理学 分类： 物理学 >> 核物理学 分类： 物理学 >> 交叉学科物理及相关领域的科学与技术 提交时间： 2024-12-24
摘要： Cerenkov detector has its advantage to construct the reaction vertex and incident direction of the energetic particles, and thus to locate the emission source. We propose to measure the neutrino source by modular photomultiplier tube (PMT) array using clean and transparent deep sea water as sensitive medium. The feasibility of the detection of solar neutrino is demonstrated by full simulation based on Geant4 packages. The production and transport of Cerenkov photons generated by the neutrino electron scattering are simulated. Houth transform method is applied to reconstruct the vertex and the direction of the high-speed electron, as well as the incident direction of the neutrinos. The dominant background of gamma radiation from 40K in sea water can be suppressed by a factor of 10^7 if a threshold on the number of firing PMTs is introduced. The total reconstruction efficiency increases with the incident energy, reaching 25% for 6 MeV neutrino and 52% for 10 MeV neutrino, respectively. To locate an existing neutrino source, a certain number of neutrino events are required, depending on the background intensity above the threshold. The simulation results reveal how feasible to measure solar neutrino using deep sea water.
分类： 物理学 >> 基本粒子与场物理学 分类： 地球科学 >> 空间物理学 提交时间： 2024-12-13
摘要： 针对引力在四大基本力大统一方面出现的广义相对论与量子力学矛盾的问题。认为广义相对论否定超距力(引力)的论据成立，即空间是一有机的物质整体，星体只是一个密度高的物质体，而空气则是密度低的物质体，星体是以转动惯量为特征由微小物体在空间自然惯动自然发展起来的，期间以其惯动的空气旋流(惯涌力矩)归并其它物体逐渐壮大，根据质能方程空间物体惯动的动能来自其自身的质量与速度。星体是由冰疑态、气疑态、岩疑态和核疑态的基本阶段递进变化的，即是一个星体质量密度逐渐增加的阶段，其实质是星体惯动的动能使其内部的物质逐渐挤压至其逐渐精华的过程。岩疑态阶段在地球浅层可从矿石中获得大量金属物质，其中含有充足电子，这微小粒子的高速运动可转换为较大的能量，这就是电磁力的效果；核疑态是在岩疑态惯动挤压形成的含有原子的核物质，在进一步的惯动挤压下产生原子核聚变发光释放最精化的能量形式，这就是强、弱相互作用力的效果。显然，因为对具有不同能量微观粒子(电子与原子)作力的统一要有许多设定条件，而要微观粒子的力将与性质完全不同的惯涌力作统一是不可能的。所以用产生效果的动能来统一四大基本力逻辑性更准确。综合起来，力是质量与自然运动的产物，四大基本力源于星体(物质体)在空间自然惯动的动能聚积的结果，力只是物质体聚能量的表征，具有从低能至高能的发展过程，用聚能论点可更好地理解力大统一自然界的力源。
分类： 物理学 >> 基本粒子与场物理学 提交时间： 2024-12-09
摘要： 本文介绍了一种新颖的粒子流场理论。该理论的基础不是质点模型和惯性参照系，而是弹性粒子（实粒子）模型和质心参照系。本文应用矢量分析在运动粒子空间中导出了一组完整的流场方程。它揭示了质心系中电荷和质量之间的可比关系，从而融合了引力和电磁相互作用。该理论证明量子随机性源于质心系中时间和空间测量的不确定性，这种不确定性可以通过测量原理加以消除，从而得出确定性的结论。本文所提出的理论为各种基本物理问题提供了独特的解决方案和诠释基础，如物体的结构、暗物质的存在、光的本性和黑体辐射现象。尤其是宇宙电子流体的存在挑战了人们传统认知，并对现有物理定律产生重大影响。
分类： 物理学 >> 基本粒子与场物理学 提交时间： 2024-10-12
摘要： Einstein-Maxwell gravity theory is well defined and be familiar with lots of theorist. How about a coherent consideration of Einstein-Maxwell gravity theory with magnetic moment term? This paper gives a first introduction of Einstein-Maxwell gravity theory with SU(4) gauge field magnetic moment term, and the nonzero eletro-magnetic parts of SU(4) gauge field magnetic moment term with EinsteinMaxwell gravity theory is analysed.
分类： 物理学 >> 基本粒子与场物理学 分类： 物理学 >> 地球物理学、天文学和天体物理学 提交时间： 2024-09-27
摘要： demonstrates that the common-spectrum process is duecosmological phase transition [6].12.5-year data[13]that contained the first reportedevidence for a common spectrum process in the nHzrange [14-16] that was subsequently confirmed by otherPTAs「17-19].In this paper we revisit cosmic strings inmodate the updated NANOGrav data as well as otherders of magnitude in frequency,whereas the extensionof the SMBH binary model to higher frequencies is sub-ject to larger uncertainties [20].Our aim in this paper,therefore,is to explore the robustness of the cosmic stringpredictions and whether it can avoid making testable pre-dictions for higher-frequency GW detectors.
分类： 物理学 >> 基本粒子与场物理学 提交时间： 2024-09-04
摘要： In this paper, we mainly discuss analytical expressions of positive definiteness for a special 4th order 3-dimensional symmetric tensor defined by the constructed model for a physical phenomenon. Firstly, an analytically necessary and sufficient conditions of 4th order 2-dimensional symmetric tensors are given to test its positive definiteness. Furthermore, by means of such a result, a necessary and sufficient condition of positive definiteness is obtained for a special 4th order 3-dimensional symmetric tensor. Such an analytical conditions can be used for verifying the vacuum stability of general scalar potentials of two real singlet scalar fields and the Higgs boson. The positive semi-definiteness conclusions are presented too.
分类： 物理学 >> 普通物理:统计和量子力学,量子信息等 分类： 物理学 >> 基本粒子与场物理学 提交时间： 2024-08-27
摘要： We propose a simple, direct and verifiable explanation for the neutrino oscillations. This explanation is based on the exchange effect between identical particles. Specifically, the experimental neutrinos acquire a tiny potential energy inversely proportional to their energy by exchanging with the Cosmic Neutrino Background (CνB). This exchange occurs both between neutrinos of the same flavour and between neutrinos of different flavours, and the latter makes the three potential energy eigenstates of the experimental neutrinos different from the three flavour eigenstates. In terms of the effect on the phase factor of the wave function, a neutrino having a tiny potential energy inversely proportional to its energy is equivalent to it having a tiny apparent mass, and the potential eigenstates being a mixture of flavour eigenstates is equivalent to the mass eigenstates being a mixture of flavour eigenstates. We calculate the potential eigenvalues and eigenstates of the potential energy matrix expressed by the exchange amplitudes between the experimental neutrinos and the CνB, and determine the matrix (with one free parameter) by using the measurement data of the neutrino oscillation experiments. The values of the matrix elements have the features that are consistent with the prediction of the Standard Cosmological Model (SCM) for the distribution of the CνB. In addition, the SCM predicts the magnitude of the background neutrino flux, and according to our theory, if the flux of experimental neutrinos is much larger than that of the background neutrinos, then the neutrino exchange may change the distribution of the background neutrinos, and thus change the apparent mass of the neutrinos as well as the way of mixing. This provides a new and unified perspective to explain various anomalies in experiments involving high-flux neutrino sources. Systematically studying the relationship between these anomalies and the magnitude of neutrino flux through experiments would provide a realistic way to test our theory.
分类： 物理学 >> 基本粒子与场物理学 分类： 物理学 >> 核物理学 提交时间： 2024-06-20
Xiaozhou Yu
Xiyang Wang
Weihu Ma
Shihong Fu
Pengfei Sun
Jinxing Song
Wanbin He
Yang Shen
Long Ma
Jinhui Chen
Huan Zhong Huang
Siguang Wang
Jing Zhou
Xiaomei Li
摘要： The sPHENIX experiment is a new generation of large acceptance detector at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory with scientific goals focusing on probing the strongly interacting Quark-Gluon Plasma (QGP) with hard probes of jets, open heavy flavor particles and $ Upsilon$ production. The EMCal detector, covering the pseudo-rapidity region of $ eta leq 1.1$, is an essential subsystem of sPHENIX. In this paper, we focus on the production and test for the EMCal blocks covering a pseudo-rapidity of $ eta in 0.8 , 1.1 $. These, in conjunction with central pseudo-rapidity EMCal blocks, significantly enhance the sPHENIX physics capability of jet and $ Upsilon$ particle measurements. In this paper, detector module production and testing of the sPHENIX W-powder/Scintillating Fiber (W/ScFi) Electromagnetic Calorimeter Blocks are presented. Selection of the tungsten powder, mold fabrication, QA procedures and cosmic ray test results are discussed.
分类： 物理学 >> 核物理学 分类： 物理学 >> 基本粒子与场物理学 提交时间： 2024-04-15
摘要： 在相对论重离子碰撞中寻找手征磁效应（CME）有助于我们理解强相互作用中的CP对称性破缺和量子色动力学（QCD）真空的拓扑性质。基于CME的背景和信号相对于旁观者平面和参与者平面有不同的相关性，实验上提出了一种双平面方法提取CME信号。利用具有不同强度CME的多相输运模型，我们在质心碰撞能量为200 GeV的同质异位素碰撞中重新探讨了双平面方法，发现相对于两个不同平面的CME信号和背景效应的比值系数是不同的，这与目前实验测量中的假设不一致。这种差异来自于相对于旁观者和参与者平面的CME的退关联，它源于末态的相互作用。我们的发现表明，目前的实验测量可能高估了在相对论性重离子碰撞中观测到的末态CME信号的比例。
分类： 信息科学与系统科学 >> 信息科学与系统科学基础学科 分类： 物理学 >> 电磁学、光学、声学、传热、经典力学和流体动力学 分类： 电子与通信技术 >> 光电子学与激光技术 分类： 物理学 >> 地球物理学、天文学和天体物理学 分类： 物理学 >> 基本粒子与场物理学 提交时间： 2024-04-08
摘要： The Einstein’s theory of special relativity is based on his two postulates. The first is that the laws of physics are the same in all inertial reference frames. The second is that the velocity of light in the vacuum is the same in all inertial frames. The theory of special relativity is considered to be supported by a large number of experiments. This paper revisits the two postulates according to the new interpretations to the exact solutions of moving sources in the laboratory frame. The exact solutions are obtained using the classic Maxwell’s theory, which clearly show that the propagation velocity of the electromagnetic waves of moving sources in the vacuum is not isotropic; the propagation velocity of the electromagnetic waves and the moving velocity of the sources cannot be added like vectors; the transverse Doppler effect is intrinsically included in the fields of the moving sources. The electromagnetic sources are subject to the Newtonian mechanics, while the electromagnetic fields are subject to the Maxwell’s theory. We argue that since their behaviors are quite different, it is not a best choice to try to bind them together and force them to undergo the same coordinate transformations as a whole, like that in the Lorentz transformations. Furthermore, the Maxwell’s theory does not impose any limitations on the velocity of the electromagnetic waves. To assume that all objects cannot move faster than the light in the vacuum need more examinations. We have carefully checked the main experiment results that were considered as supporting the special relativity. Unfortunately, we found that the experimental results may have been misinterpreted. We here propose a Galilean-Newtonian-Maxwellian relativity, which can give the same or even better explanations to those experimental results.
分类： 物理学 >> 基本粒子与场物理学 提交时间： 2024-03-08
摘要： Basing on Mellin-Barnes representations and Miller’s transformation, we present the Gel’fand-Kapranov-Zelevinsky (GKZ) hypergeometric systems of the four-loop vacuum Feynman integrals with arbitrary masses. Through the GKZ hypergeometric systems, the analytical hypergeometric series solutions of the four-loop vacuum Feynman integrals with arbitrary masses can be obtained in neighborhoods of origin including infinity. The analytical expressions of the four-loop vacuum Feynman integrals can be formulated as a linear combination of the corresponding fundamental solution systems in certain convergent region.
分类： 物理学 >> 基本粒子与场物理学 分类： 物理学 >> 核物理学 提交时间： 2024-03-07
摘要： 在硅像素探测器的研究和开发中，配备高分辨率的像素束望远镜的准直单能带电粒子测试束流对探测器原型验证和性能评估是至关重要的。当束流能量较低时，必须考虑多次库仑散射对被测设备（DUT）测量分辨率的影响，以准确评估像素芯片和探测器的性能。本研究旨在调查多次库仑散射对DUT测量分辨率的影响，特别是在低束流能量下。使用Allpix2软件进行模拟，研究了不同束流能量、物质量和望远镜布局下多次库仑散射的影响。模拟还提供了多次库仑散射影响可忽略的最低能量。与在DESY用电子束测试的的结果相比，模拟结果与束流测试结果一致，验证了模拟的可靠性。
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