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
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: 物理学 >> 基本粒子与场物理学 提交时间: 2024-04-10
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: 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。
分类: 物理学 >> 基本粒子与场物理学 提交时间: 2024-01-25
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: 2023-12-04
摘要: In this paper, the analytic sufficient and necessary conditions are obtained for the CP conserving two-Higgs-doublet potential to be bounded from below by using the co-positivity of tensors. This is achieved by treating the potential as a quartic homogeneous polynomial about the moduli of the two Higgs doublet fields, where the angles is described as the misalignment of the two doublets, then solving three minimum problems with respect to the misalignment. Finally, the analytic conditions are established with the help of the corresponding theory and methods of higher order tensors.
分类: 物理学 >> 基本粒子与场物理学 提交时间: 2023-12-04
摘要: In this paper, we present how to calculate the bounded from below or the vacuum stability of scalar potential for a general CP violating two-Higgs-doublet model by using the concepts of co-positivity and the gauge orbit spaces. Meanwhile, the semi-positive definiteness is prove for a class of 4th-order 2-dimensional complex tensor.
分类: 物理学 >> 基本粒子与场物理学 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: 2023-04-10
摘要: 本文回顾了推导达朗贝尔波动方程的全过程,其中最重要的一步是用高斯定律和安培定律,分别导出了标势和矢势的达朗贝尔波动方程。本文强调:高斯定律是库伦定律的微分形式,其中的源电荷与观测者即场点是相对静止的;在安培定律中,源电流载体与观测者即场点也是相对静止的。本文的结论是:麦克斯韦方程组和达朗贝尔波动方程都是在源-观相对静止条件下的方程,达朗贝尔波动方程中的常数C是在真空环境中,源-观相对静止条件下的传播速度。 在这样的特殊条件下,电磁波的传播空间是均匀和各向同性的,因此,无论传播的距离和方位几何,无论源-观所在的实验室位于哪个星球上,绝对运动如何,电磁波传播速度都相同,这是合乎逻辑的。 真空中的电磁波从源电荷、源电流发出,向各处的观测者传播,源-观相对静止,传播空间均匀而各向同性的,这是一个准确的物理图像,是准确理解光速不变原理的物理基础。
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: 2022-10-16
摘要:
It is reported that the Large High Altitude Air Shower Observatory (LHAASO) observed thousands 9 of very-high-energy photons up to ∼18 TeV from GRB 221009A. We study the survival rate of these 10 photons by considering the fact that they are absorbed by the extragalactic background light. By performing a set of 10 11 6 Monte-Carlo simulations, we explore the parameter space allowed by current 12 observations and find that the probability of predicting that LHAASO observes at least one photons 13 of 18 TeV from GRB 221009A within 2000 seconds is 4–5%. Hence, it is still possible for the standard 14 physics to interpret LHAASO’s observation in the energy range of several TeV. Our method can be 15 straightforwardly generalized to study more data sets of LHAASO and other experiments in the future.
分类: 物理学 >> 基本粒子与场物理学 提交时间: 2022-07-28
摘要: Komar积分公式可以方便地用于定义渐近平直时空的质量与角动量。但是,二者的表达式在形式上不一致,彼此之间存在一个差异因子。为了消除这种不一致性,采用把保持微分形式次不变的微分算子作用于1-形式矢量场来生成守恒流的方法,得到了含Killing矢量非线性三阶导数项的修正Komar势。基于该势的守恒荷定义实现了渐近平直时空的质量与角动量在形式上的一致性。
分类: 物理学 >> 基本粒子与场物理学 提交时间: 2022-06-21
摘要: In this article, I shall propose an enlightening view on the origin of dark matter abundance, in which I introduce a neutral primordial field, which is a new field beyond the standard model, the mass of the primordial field is confined in the vicinity of neutrino mass (or 1-2 orders of magnitude different from the neutrino mass). All the standard model elementary particles are produced spontaneously from this field in the Big Bang epoch of the universe and then these produced elementary particles decayed or annihilated in the well-known standard model interactions. The relic of the primordial field appears in a form of vacuum energy can not only give naturally the correct abundance of dark matter in the present universe, but provide a natural solution to the cosmological constant problem as well. We find that the conventional methods of detecting dark matter either fail or have great difficulties to detect the remaining vacuum energy of the primordial field, and how to confirm the existence of the remaining energy of the universe's original energy in experiment is still an open problem.
分类: 物理学 >> 基本粒子与场物理学 提交时间: 2021-10-16
摘要: 提出马赫思想的一种表述,并讨论了压强对时空弯曲的影响,由此得到如下一些结果。第一,有一部分类星体由于其非宇宙学红移而成为伪类星体;第二,对暗物质存在的部分依据如旋涡星系转动曲线、宇宙结构形成等给出非暗物质的理解;第三,预期沿银河系径向高速运动粒子静惯性质量会发生改变、地球绕日轨道和月球绕地轨道会出现微小畸变;第四,计算表明孤立恒星、星系和星系团可能具有广义相对论二十余倍的引力透镜效应;第五, 黑洞奇点有可能避免;第六,给出宇宙一种周期性演化模型。在这种模型中虽然宇宙演化的发散奇点不可能避免,但测地线完备可能保持,并且不需要暗能量当今宇宙仍可能处于加速膨胀阶段。该模型不存在视界疑难和平直性疑难。最后,探讨了引力波源是否可多信道探测的问题。
分类: 物理学 >> 基本粒子与场物理学 提交时间: 2021-02-26
摘要: 本文对理想气体与真空的类比研究。在这种类比下,质量来源于流体的漂移质量,而一定的假设下,质能方程及质速关系也能得到,并进一步可导出洛伦兹变换。
分类: 物理学 >> 基本粒子与场物理学 提交时间: 2020-11-02
摘要: In this note, we investigate the anomalies in field theories. The results of the anomalies through Feynman diagrams calculation are multi-valued function. These single-valued branches of multi-valued function are related to the bound states of neutral pseudoscalar mesons. Adding these bound state contributions, we obtain a new anomaly free condition that all the external particles are on-shell and find the non-perturbative mass spectrum of neutral pseudoscalar mesons. We also discuss the anomaly in 2 dimensional QFT.
分类: 物理学 >> 基本粒子与场物理学 提交时间: 2020-09-17
摘要: In this work, we try to find a way to describe the physical law of micro-world under the frame of a space-time theory. By introducing a scalar field D(x), we rewrite the action of conventional field theory and the Lagrangian describing the motion of the particle, where a modified space-time relation is obtained. To prove the correctness of this attempt, we derive the Klein-Gordon equation by the Hamilton-Jacobi method in four dimensional form.
分类: 物理学 >> 基本粒子与场物理学 提交时间: 2020-09-06
摘要: We regard the background of space-time as a physical system composed of discrete volume elements at the Planck scale and get the internal energy of space-time by Debye model. A temperature-dependent minimum energy limit of the particles is proposed from the thermal motion part of the internal energy. As decreases of the temperature caused by the expansion of the universe, more and more particles would be "released" because of the change of the energy limit, we regard these new particles as a source of dark energy. The minimum energy limit also leads to a corrected number of particles in universe and a modified conservation equation. According to the modified conservation equation, an effective cosmological constant consistent with its observed value is obtained.
分类: 物理学 >> 基本粒子与场物理学 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: 2020-03-13
摘要: The interactions between waves and electrons are the basis of vacuum tubes and particle accelerators. In order to further understand the interactions, we proposed a new electromagnetic model. In this model, the photon is composed of two elementary particles – ephoton and mphoton, which are the basic particles that form the electric fields and magnetic fields, respectively. There are many ephotons around the electrons and the electrons can absorb the ephotons. The proposed electromagnetic model can well explain the electromagetic phenomena and the interactions between waves and electrons.
分类: 物理学 >> 基本粒子与场物理学 分类: 数学 >> 数学物理 提交时间: 2018-10-08
摘要: 本文系统地探讨了霍奇星算子与外微分算符作用于任意微分形式场时两者的一般组合规律。首先,找到了保持微分形式场的次不变的两个组合算符,并通过二者的线性组合得到了一个新算符。其次,当由任意数目的霍奇星算子与外微分算符进行组合时,作者导出了所有形式上彼此互异的组合算符的统一表达式,这些表达式由单个霍奇星算子与外微分算符以及二者的任选两个的非零组合构成。在此基础上,分析了所有算符之间的相互作用关系,并根据这些算符对微分形式的次的改变情况,对它们进行了具体分类。最后,作为一个应用,作者详细讨论了如何由次相同的微分形式的线性组合来构造电磁场的麦克斯韦方程。