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0. Unbinned inclusive cross-section measurements with machine-learned systematic uncertaintiesid:2505.05544:id在线阅读
Lisa Benato, Cristina Giordano, Claudius Krause, Ang Li, Robert Schöfbeck, Dennis Schwarz, Maryam Shooshtari, Daohan Wang
We introduce a novel methodology for addressing systemat...点击展开阅读
0. Unbinned inclusive cross-section measurements with machine-learned systematic uncertaintiesid:2505.05544:id在线阅读
Lisa Benato, Cristina Giordano, Claudius Krause, Ang Li, Robert Schöfbeck, Dennis Schwarz, Maryam Shooshtari, Daohan Wang
We introduce a novel methodology for addressing systematic uncertainties in unbinned inclusive cross-section measurements and related collider-based inference problems. Our approach incorporates known analytic dependencies on parameters of interest, including signal strengths and nuisance parameters. When these dependencies are unknown, as is frequently the case for systematic uncertainties, dedicated neural network parametrizations provide an approximation that is trained on simulated data. The resulting machine-learned surrogate captures the complete parameter dependence of the likelihood ratio, providing a near-optimal test statistic. As a case study, we perform a first-principles inclusive cross-section measurement of $\textrm{H}\rightarrow\tau\tau$ in the single-lepton channel, utilizing simulated data from the FAIR Universe Higgs Uncertainty Challenge. Results in Asimov data, from large-scale toy studies, and using the Fisher information demonstrate significant improvements over traditional binned methods. Our computer code ``Guaranteed Optimal Log-Likelihood-based Unbinned Method'' (GOLLUM) for machine-learning and inference is publicly available.
我们介绍了一种新方法,用于解决无分度包容截面测量中的系统不确定性以及相关的基于对撞机的推断问题。我们的方法结合了相关参数的已知分析依赖关系,包括信号强度和干扰参数。当这些依赖关系未知时,如系统不确定性经常出现的情况,专用神经网络参数化提供了一个近似值,并在模拟数据上进行训练。由此产生的机器学习代用参数捕捉了似然比的完整参数依赖性,提供了接近最优的测试统计量。作为案例研究,我们利用 "FAIR宇宙希格斯不确定性挑战 "的模拟数据,对单轻子信道的$\textrm{H}\rightarrow\tau\tau$进行了第一原理包容截面测量。阿西莫夫数据中的结果、大规模玩具研究中的结果以及使用费舍尔信息的结果表明,与传统的二进制方法相比,我们的结果有了显著的改进。我们用于机器学习和推理的计算机代码 "Guaranteed Optimal Log-Likelihood-based Unbinned Method'' (GOLLUM) "已公开发布。
1. Correlating the $B$ anomalies to $K\to πν\barν$ and $B\to Kν\barν$ via leptoquarksid:2505.05552:id在线阅读
Andreas Crivellin, Syuhei Iguro, Teppei Kitahara
Leptoquark models are prime candidates for new physics (NP) explanations of the long-standing anomalies in semi-leptonic $B$ decays; $b\to c \tau \bar\nu$ (encoded in $R(D^{(\ast)})$) and $b\to s\ell\bar\ell (\ell=e,\mu)$ transitions. Furthermore, Belle II and NA62 reported weaker-than-expected limits on $B^+ \to K^+ \nu\bar\nu$ and $K^+ \to \pi^+ \nu \bar\nu$, respectively. While the $R(D^{(\ast)})$ and $b\to s\ell \bar\ell$ measurements can be explained with NP contributions at the $O(10\%)$ level, the neutrino channels suggest that the NP effect could be comparable in size to the Standard Model one. In this context, we consider the two types of leptoquark models with minimal sets of the couplings that can best describe the semi-leptonic $B$ anomalies and lead at the same time to effects in the neutrino modes, the singlet-triplet scalar leptoquark model ($S_1+S_3$) and the singlet vector leptoquark model ($U_1$). More specifically, the neutrino channels pose non-trivial constraints on the parameter space, and we find that large effects (i.e., accounting for the current central value) in $B\to K^{(*)}\nu\bar\nu$ are only possible in the $S_1+S_3$ setup, while both models can account for the central value of $K^+\to \pi^+\nu\bar\nu$.
对于半轻子$B$衰变中长期存在的异常现象--$b\to c \tau \bar\nu$(在$R(D^{(\ast)})$中编码)和$b\to sell\bar\ell (\ell=e,\mu)$转变--来说,后夸克模型是新物理学(NP)解释的主要候选者。此外,Belle II 和 NA62 分别报告了 $B^+ \to K^+ \nu\bar\nu$ 和 $K^+ \to \pi^+ \nu \bar\nu$ 的极限弱于预期。虽然$R(D^{(\ast)})$和$b\to s\ell \bar\ell$ 测量可以用$O(10\%)$水平的NP贡献来解释,但中微子信道表明NP效应的大小可能与标准模型效应相当。在此背景下,我们考虑了两类具有最小耦合集的轻夸克模型,它们可以最好地描述半轻子$B$异常,并同时导致中微子模式的效应,即单子-三子标量轻夸克模型($S_1+S_3$)和单子矢量轻夸克模型($U_1$)。更具体地说,中微子信道对参数空间构成了非同小可的约束,我们发现只有在$S_1+S_3$设置中才可能出现$B\to K^{(*)}\nu\bar\nu$的大效应(即占当前中心值),而这两种模型都可以占$K^+\to \pi^+\nu\bar\nu$的中心值。
2. A Fresh Look at the Diffuse ALP Background from Supernovaid:2505.05567:id在线阅读
Francisco R. Candón, Sougata Ganguly, Maurizio Giannotti, Tanmoy Kumar, Alessandro Lella, Federico Mescia
Proto-neutron stars, highly compact objects formed in the core of exploding supernovae (SNe), are powerful sources of axion-like particles (ALPs). In the SN core, ALPs are dominantly produced via nucleon-nucleon bremsstrahlung and pion conversion, resulting in an energetic ALP spectrum peaked at energies $\mathcal{O}(100)\,\rm MeV$. In this work, we revisit the diffuse ALP background, produced from all past core-collapse supernovae, and update the constraints derived from Fermi-LAT observations. Assuming the maximum ALP-nucleon coupling allowed by the SN 1987A cooling, we set the upper limit $g_{a \gamma \gamma} \lesssim 2 \times 10^{-13}\,\rm GeV^{-1}$ for ALP mass $m_a\lesssim 10^{-10}\,\rm eV$, which is approximately a factor of two improvement with respect to the existing bounds. On the other hand, for $m_a \gtrsim 10^{-10}\,\rm eV$, we find that including pion conversion strengthens the bound on $g_{a\gamma \gamma}$, approximately by a factor of two compared to the constraint obtained from bremsstrahlung alone. Additionally, we present a sensitivity study for future experiments such as AMEGO-X, e-ASTROGAM, GRAMS-balloon, GRAMS-satellite, and MAST. We find that the expected constraint from MAST would be comparable to Fermi-LAT bound. However, SN 1987A constraint remains one order of magnitude stronger as compared to the bound derived from the current and future gamma-ray telescopes.
原中子星是在超新星(SNe)爆炸的内核中形成的高度紧凑的天体,是类轴子粒子(ALPs)的强大来源。在SN内核中,ALPs主要是通过核子-核子轫致辐射和先驱转换产生的,从而导致高能ALP频谱在能量$\mathcal{O}(100)\,\rm MeV$处达到峰值。在这项工作中,我们重新审视了由过去所有的核坍缩超新星产生的弥散ALP背景,并更新了从费米-LAT观测中得出的约束条件。假定SN 1987A冷却所允许的最大ALP-核子耦合,我们为ALP质量$m_a(lesssim 10^{-10}\\rm eV)设定了上限$g_{a(\gamma \gamma} (lesssim 2 \times 10^{-13}\,\rm GeV^{-1}$,这与现有的约束相比大约提高了两倍。另一方面,对于 $m_a \gtrsim 10^{-10}\,\rm eV$,我们发现包括先驱转换会加强对 $g_{a\gamma \gamma}$ 的约束,与仅从轫致辐射得到的约束相比,大约提高了两倍。此外,我们还对未来的实验,如AMEGO-X、e-ASTROGAM、GRAMS-气球、GRAMS-卫星和MAST,进行了敏感性研究。我们发现,MAST的预期约束与费米-LAT约束相当。然而,与目前和未来的伽马射线望远镜得出的约束相比,SN 1987A的约束仍然要强一个数量级。
3. The Electroweak Sphaleron Revisited: I. Static Solutions, Energy Barrier, and Unstable Modesid:2505.05607:id在线阅读
Konstantin T. Matchev, Sarunas Verner
The electroweak sphaleron is a static, unstable solution of the Standard Model classical field equations, representing the energy barrier between topologically distinct vacua. In this work, we present a comprehensive updated analysis of the sphaleron using current Standard Model parameters with the physical Higgs boson mass of $m_H = 125.1$ GeV and $m_W = 80.4$ GeV, rather than the $m_H = m_W$ approximation common in earlier studies. The study includes: (i) a complete derivation of the $SU(2)\times U(1)$ electroweak Lagrangian and field equations without gauge fixing constraints, (ii) high-precision numerical solutions for the static sphaleron configuration yielding a sphaleron energy $E_{\rm{sph}} \simeq 9.1$ TeV, (iii) an analysis of the minimum energy path in field space connecting the sphaleron to the vacuum (a 1D potential barrier as a function of Chern-Simons number), and (iv) calculation of the sphaleron single unstable mode with negative eigenvalue $\omega^2_{-} = -2.7m^2_W$, providing analytical fits for its eigenfunction. We find that using the measured Higgs mass modifies the unstable mode frequency, with important implications for baryon number violation rates in both early universe cosmology and potential high-energy collider signatures. These results provide essential input for accurate lattice simulations of sphaleron transitions and precision calculations of baryon number violation processes.
电弱螺旋是标准模型经典场方程的一个静态、不稳定解,代表拓扑学上不同真空之间的能量屏障。在这项工作中,我们使用希格斯玻色子物理质量为 $m_H = 125.1$ GeV 和 $m_W = 80.4$ GeV 的当前标准模型参数,而不是早期研究中常见的 $m_H = m_W$ 近似值,对闪龙进行了全面的更新分析。研究内容包括(i) 在没有量规固定约束的情况下,完整地推导出了 $SU(2)\times U(1)$ 电弱拉格朗日和场方程;(ii) 静态头鹭构型的高精度数值解,得出了头鹭能量 $E_{\rm{sph}} 。\simeq 9.1$ TeV,(iii) 分析场空间中连接头鹭和真空的最小能量路径(作为切尔-西蒙斯数函数的一维势垒),(iv) 计算具有负特征值$\omega^2_{-} = -2.7m^2_W$的头鹭单一不稳定模式,为其特征函数提供分析拟合。我们发现,使用测得的希格斯质量会改变不稳定模式的频率,这对早期宇宙学中的重子数违反率和潜在的高能对撞机特征都有重要影响。这些结果为精确的晶格模拟闪子跃迁和重子数违反过程的精密计算提供了重要输入。
4. The Electroweak Sphaleron Revisited: II. Study of Decay Dynamicsid:2505.05608:id在线阅读
Konstantin T. Matchev, Sarunas Verner
We present a comprehensive analysis of electroweak sphaleron decay dynamics, employing both analytical techniques and high-resolution numerical simulations. Using a spherically symmetric ansatz, we reformulate the system as a $(1+1)$-dimensional problem and analyze its stability properties with current Standard Model parameters ($m_H = 125.1$ GeV, $m_W = 80.4$ GeV). We identify precisely one unstable mode with eigenvalue $\omega_{-}^2 \simeq -2.7m_W^2$ and numerically evolve the full non-linear field equations under various initial conditions. Through spectral decomposition, we quantify the particle production resulting from the sphaleron decay. Our results demonstrate that the decay process is dominated by transverse gauge bosons, which constitute approximately 80% of the total energy and multiplicity, while Higgs bosons account for only 7-8%. On average, the sphaleron decays into 49 $W$ bosons and 4 Higgs bosons. The particle spectra consistently peak at momenta $k \sim 1 - 1.5 \, m_W$, reflecting the characteristic size of the sphaleron. Remarkably, these properties remain robust across different decay scenarios, suggesting that the fundamental structure of the sphaleron, rather than specific triggering mechanisms, determines the decay outcomes. These findings provide distinctive experimental signatures of non-perturbative topological transitions in the electroweak theory, with significant implications for baryon number violation in the early universe and potentially for high-energy collider physics.
我们采用分析技术和高分辨率数值模拟,对电弱化子衰变动力学进行了全面分析。利用球对称解析,我们把系统重新表述为一个 $(1+1)$ 维问题,并分析了它在当前标准模型参数($m_H = 125.1$ GeV,$m_W = 80.4$ GeV)下的稳定性。我们精确地确定了一个特征值为$\omega_{-}^2 \simeq -2.7m_W^2$的不稳定模式,并在各种初始条件下对整个非线性场方程进行了数值演化。通过谱分解,我们量化了sphaleron 衰变产生的粒子。我们的结果表明,衰变过程由横向规玻色子主导,约占总能量和倍率的 80%,而希格斯玻色子只占 7-8%。平均而言,sphaleron 衰变为 49 个 $W$ 玻色子和 4 个希格斯玻色子。粒子谱始终在时刻$k \sim 1 - 1.5 \, m_W$处达到峰值,反映了sphaleron的特征尺寸。值得注意的是,这些特性在不同的衰变情况下都能保持稳定,这表明决定衰变结果的是头旋子的基本结构,而不是特定的触发机制。这些发现为电弱理论中的非微扰拓扑跃迁提供了独特的实验特征,对早期宇宙中的重子数违反以及潜在的高能对撞机物理具有重要意义。
5. A Physics Model for Origin of Lifeid:2505.05634:id在线阅读
Paul Howard Frampton
In this article, we attempt to convince the reader that the origin of life was such an exceptionally unlikely event that it probably has never occurred elsewhere. This involves an explicit calculation using the laws of physics which, while speculative, may encapsulate the essential science without knowledge of biological details. Making only physics, and no biology, assumptions about the origin of the first single celled organism (SCO) on Earth, we adopt methods of quantum tunnelling to make an estimate of the probability ${\cal P}_{SCO}$ for the origin of life. We argue that before the time $t_{SCO}$ laws of physics must suffice and assume a first-order phase transition which nucleates at the first SCO production. In the classical limit where Planck's constant vanishes $h\rightarrow0$, ${\cal P}_{SCO}$ also vanishes and remains extremely small for the correct value of $h$. Thus quantum mechanics plays a central role in permitting life to form. We compare the resultant probability with the expected number of exoplanets in the Milky Way ($\sim10^{12}$) and the Visible Universe ($\sim10^{24}$) and conclude that the probability of extraterrestrial life in the Visible Universe is infinitesimal. This result suggests that the visible universe is a lonely place for humankind because extraterrestrial life will never be encountered.
在这篇文章中,我们试图让读者相信,生命的起源是一个极其不可能发生的事件,它很可能从未在其他地方出现过。这需要利用物理定律进行明确的计算,虽然是推测,但可以在不了解生物细节的情况下概括基本的科学知识。在对地球上第一个单细胞生物(SCO)的起源只做物理学假设而不做生物学假设的前提下,我们采用量子隧穿方法对生命起源的概率 ${\cal P}_{SCO}$ 进行了估计。我们认为,在时间 $t_{SCO}$ 之前,物理定律必须足够,并假设一阶相变在第一次 SCO 产生时就已成核。在普朗克常数$h/rightarrow0$消失的经典极限中,${cal P}_{SCO}$也会消失,并且在正确的$h$值下保持极小。因此,量子力学在生命形成的过程中起到了核心作用。我们将得出的概率与银河系($\sim10^{12}$)和可见宇宙($\sim10^{24}$)中系外行星的预期数量进行了比较,得出的结论是:可见宇宙中出现地外生命的概率微乎其微。这一结果表明,可见宇宙对于人类来说是一个孤独的地方,因为人类永远不会遇到地外生命。
6. From oversimplified to overlooked: the case for exploring Rich Dark Sectorsid:2505.05663:id在线阅读
Asli Abdullahi, Francesco Costa, Andrea Giovanni De Marchi, Alessandro Granelli, Jaime Hoefken-Zink, Matheus Hostert, Michele Lucente, Elina Merkel, Jacopo Nava, Silvia Pascoli, Salvador Rosauro-Alcaraz, Filippo Sala
The Standard Model (SM) of particle physics provides a very successful description of fundamental particles and their interactions but it is incomplete, as neutrino masses, dark matter and the baryon asymmetry of the Universe indicate. In addition, the origin of masses and of the approximate fundamental symmetries call out for deeper explanations. The quest for a New SM Theory, that extends the SM to a more general theory, is ongoing. For decades the main focus has been on the TeV scale, but despite an impressive theoretical and experimental effort, no hints of new physics at such scale has been found in experiments.
粒子物理学标准模型(SM)非常成功地描述了基本粒子及其相互作用,但正如中微子质量、暗物质和宇宙重子不对称所表明的那样,它并不完整。此外,质量和近似基本对称性的起源也需要更深入的解释。人们一直在探索一种新的 SM 理论,它将 SM 扩展为一种更广义的理论。几十年来,人们一直把主要焦点放在 TeV 尺度上,但尽管在理论和实验方面做出了巨大的努力,在这样的尺度上却没有在实验中发现新物理学的蛛丝马迹。
Dark sectors provide an interesting alternative to TeV scale extensions of the SM to explain the open questions in particle and astroparticle physics. Going beyond minimal models, rich dark sectors extend the SM to a complex theory with multiple particles and interactions, in analogy to the SM itself. They have a wealth of theoretical and astrophysical/cosmological consequences and can lead to phenomenological signatures that can be markedly different to that of minimal ones. These include short-lived particles and semi-visible decay signatures, as opposed to minimal models where new states are typically long-lived and purely visible or invisible resonances. Given the experimental configurations and analysis strategies, current dark sector searches might miss such signatures. We advocate a dedicated programme of searches for rich dark sectors that overcomes the assumptions on minimality and on the long lifetime of particles and encompasses a broader range of possibilities. Here, we discuss a prototype model that includes a complex structure akin to the SM: multiple generations of fermions charged under a new spontaneously-broken gauge symmetry.
7. Synthetic Training and Representation Bridging in Reconstruction Domainsid:2505.05664:id在线阅读
Wonyong Chung
Reconstructing low-dimensional truth labels from high-dimensional experimental data is a central challenge in any scenario that relies on robust mappings across this so-called domain gap, from multi-particle final states in high-energy physics to large-scale early-universe structure in cosmological surveys. We introduce a new method to bridge this domain gap with an intermediate, synthetic representation of truth that differs from methods operating purely in latent space, such as normalizing flows or invertible approaches, in that the synthetic data is specifically engineered to represent intrinsic detector hardware capabilities of the system at hand. The hypothesis is that by encoding physical properties of the detector response available only in full simulation, such synthetic representations result in a less lossy compression and recovery than a direct mapping from truth to experimental data. We demonstrate a first implementation of this concept with full simulation of a dual-readout crystal electromagnetic calorimeter for future collider detectors, in which the synthetic data is constructed to be the simulated detector hits corresponding to photon tracks of scintillation and Cerenkov photons. We refer to these signals as simulated observables as they would not be physical observables in a real detector, but are nonetheless representations of a real physical process. First results show that the synthetic representation naturally anchors the neural network architecture to a known physical method, in this case the dual-readout correction. We believe this strategy opens new avenues for machinistic interpretability and explainability of ML-based reconstruction methods. In the case of anomalous signal detection, we hypothesize that anomalous signals detected in networks trained on synthetic data rooted in a physical process are more likely to be indicative of a genuinely physical anomaly.
从高维实验数据重构低维真实标签是任何依赖于跨越所谓领域鸿沟的稳健映射的方案所面临的核心挑战,从高能物理中的多粒子终态到宇宙学调查中的大尺度早期宇宙结构都是如此。我们引入了一种新方法,通过中间的合成真实表示来弥合这一领域差距,这种方法不同于纯粹在潜空间操作的方法,如归一化流或可逆方法,因为合成数据是专门设计来表示当前系统的内在探测器硬件能力的。我们的假设是,通过编码只有在完全模拟中才能获得的探测器响应的物理特性,这种合成表示法比从真实数据到实验数据的直接映射更能减少压缩和恢复的损失。我们通过对未来对撞机探测器的双读出晶体电磁量热计进行全仿真,展示了这一概念的首次实施,其中的合成数据是与闪烁光子和切伦科夫光子的光子轨迹相对应的模拟探测器命中。我们称这些信号为模拟观测值,因为它们不是真实探测器中的物理观测值,但却是真实物理过程的代表。初步结果表明,合成表示自然地将神经网络架构与已知的物理方法(在本例中为双读出校正)联系在一起。我们相信,这种策略为基于 ML 的重建方法的机器可解释性和可解释性开辟了新的途径。在异常信号检测方面,我们假设在基于物理过程的合成数据上训练的网络中检测到的异常信号更有可能表明真正的物理异常。
8. Vacuum pair production under spatially asymmetric time-oscillating electric fieldsid:2505.05906:id在线阅读
Mamat Ali Bake, Obulkasim Olugh
We investigate electron-positron pair production from the quantum vacuum in spatially asymmetric, time-oscillating electric fields using the Dirac-Heisenberg-Wigner (DHW) formalism. The field configuration combines spatially separated Sauter-type pulses with temporal oscillations, including frequency chirps and phase modulation. Our results demonstrate that spatial asymmetry significantly enhances pair production compared to symmetric fields, while optimal tuning of temporal parameters (e.g., frequency $\omega$ and chirp $b$) further amplifies the yield. For $\omega \gtrsim 0.4m$, multiphoton-dominated processes generate oscillatory momentum spectra, whereas low-frequency fields ($\omega \lesssim 0.3m$) exhibit tunneling-dominated Gaussian distributions. Chirped fields induce spectral asymmetry and interference patterns, with peak yields increasing by up to a factor of 9 for $\omega = 0.7m$ and $b = 0.5\omega/\tau$. These findings provide a pathway to optimize pair production in experimentally feasible spatiotemporal field configurations.
我们利用狄拉克-海森堡-维格纳(DHW)形式主义研究了量子真空中电子-正电子对在空间不对称、时间振荡电场中的产生。该电场配置结合了空间分离的萨特型脉冲和时间振荡,包括频率啁啾和相位调制。我们的研究结果表明,与对称场相比,空间不对称能显著提高配对产生率,而时间参数的优化调整(如频率$\omega$和啁啾声$b$)能进一步扩大产生率。当频率为$\omega \gtrsim 0.4m$时,多光子主导的过程会产生振荡动量谱,而低频场($\omega \lesssim 0.3m$)则表现出隧道主导的高斯分布。啁啾场会诱发频谱不对称和干涉模式,在 $\omega = 0.7m$ 和 $b = 0.5\omega/\tau$ 时,峰值产量最多可增加 9 倍。这些发现为在实验可行的时空场配置中优化光对产生提供了途径。
9. Calculation of the axial-vector coupling constant $g_A$ to two loops in covariant chiral perturbation theoryid:2505.05941:id在线阅读
Véronique Bernard, Jambul Gegelia, Shayan Ghosh, Ulf-G. Meißner
We present a calculation of the leading two-loop corrections to the axial-vector coupling constant $g_A$ in two covariant versions of two-flavor baryon chiral perturbation theory. Taking the low-energy constants from a combined analysis of elastic and inelastic pion-nucleon scattering, we find that these corrections are rather moderate.
我们介绍了在两个共变版本的双味重子手性扰动理论中对轴向-矢量耦合常数 $g_A$ 的前导二环修正的计算。通过对弹性和非弹性先锋-核子散射的综合分析,我们发现这些修正是相当温和的。
10. The light meson decays of $D$ wave charmoniaid:2505.05960:id在线阅读
Xiao-Yu Qi, Xing-Dao Guo, Dian-Yong Chen
Motivated by the large non-$D\bar{D}$ branching fraction of $\psi(3770)$, we investigate the light meson decays of the $D$-wave charmonia in the present work with the meson loop mechanism. With the parameter range determined by $\psi (3770) \to \phi \eta$, our estimations of the branching fractions of the light meson decays of $\psi(3770)$ are consistent with the estimations in the literature. As for $\psi(3823)$, the partial widths of $K^\ast \bar{K}^\ast$ channel is estimated to be around 200 keV, which is the the predominant light meson decay channel of $\psi(3823)$. Our estimations also indicate that $K^{(\ast)}\bar{K}^{(\ast)}$ and $\rho \pi$ are the dominant light meson decay modes of $\psi(3842)$, while $\eta_{c2}$ dominantly decays into $\rho\rho$, $K^\ast \bar{K}^\ast$, $\omega \omega$ and $\phi\phi$.
受$\psi(3770)$的大非$D\bar{D}$分支分数的激励,我们在本工作中用介子环机制研究了$D$波 charmonia的轻介子衰变。在$\psi(3770) \to \phi \eta$ 确定的参数范围内,我们对$\psi(3770)$ 的轻介子衰变分支分数的估计与文献中的估计一致。至于$\psi(3823)$,$K^\ast \bar{K}^\ast$ 信道的部分宽度估计在200 keV左右,这是$\psi(3823)$的主要轻介子衰变信道。我们的估计还表明,$K^{(\ast)}\bar{K}^{(\ast)}$和$\rho \pi$是$\psi(3842)$的主要轻介子衰变模式,而$\eta_{c2}$主要衰变为$\rho\rho$、$K^\ast \bar{K}^\ast$ 、$\omega \omega$ 和$\phi\phi$。
11. Beam single spin asymmetry $A_{LU}^{\sin ϕ_R}$ of the dihadron production in SIDIS processid:2505.05963:id在线阅读
Yanli Li, Keyang She, Hui Li, Xiaoyu Wang, De-Min Li, Zhun Lu
We study the longitudinal beam single-spin asymmetry $A_{LU}^{\sin \phi_R}$ of dihadron production in semi-inclusive deep inelastic scattering process with a polarized electron beam scattering off an unpolarized proton target. The asymmetry arises from the convolutions of twist-3 PDF $e(x)$ and twist-2 DiFF $H_1^\sphericalangle$ as well as twist-2 PDF $f_1(x)$ and twist-3 DiFF $\widetilde{G}^{\sphericalangle}$. Using the spectator model calculations for the twist-3 PDF $e(x)$, the DiFFs $D_1 , H_1^\sphericalangle$, and $\widetilde{G}^{\sphericalangle}$, we estimate the BSA $A^{\sin \phi_R}_{LU}$ at the kinematical configuration of CLAS and CLAS12. We find good agreement with $z$- and $M_h$-dependencies data, though $x$- and $Q^2$- dependencies show discrepancies. We include DGLAP evolution of $e(x)$ and provide predictions for COMPASS, EIC, and EicC. The negligible contribution from $f_1(x) \otimes \widetilde{G}^{\sphericalangle}$ supports the Wandzura-Wilczek approximation, while our results highlight the importance of QCD evolution in twist-3 PDF analyses.
我们研究了在半包深非弹性散射过程中,偏振电子束与非偏振质子靶发生散射时产生的纵向束单自旋不对称现象$A_{LU}^{\sin \phi_R}$。这种不对称源于扭转-3 PDF $e(x)$和扭转-2 DiFF $H_1^\sphericalangle$以及扭转-2 PDF $f_1(x)$和扭转-3 DiFF $\widetilde{G}^\{sphericalangle}$的卷积。我们使用旁观者模型计算了扭转-3 PDF $e(x)$、D_1 , H_1^\sphericalangle$ 和 $\widetilde{G}^{sphericalangle}$ ,估计了 CLAS 和 CLAS12 运动构型下的 BSA $A^{sin \phi_R}_{LU}$。我们发现与$z$-和$M_h$-相关的数据有很好的一致性,但与$x$-和$Q^2$-相关的数据有差异。我们包括了 $e(x)$ 的 DGLAP 演化,并为 COMPASS、EIC 和 EicC 提供了预测。$f_1(x) \otimes \widetilde{G}^{\sphericalangle}$ 的贡献可以忽略不计,这支持了 Wandzura-Wilczek 近似,同时我们的结果突出了 QCD 演化在扭转-3 PDF 分析中的重要性。
12. Mass spectrum of heavy tetraquarks in variational approachid:2505.05993:id在线阅读
A. V. Eskin, A. P. Martynenko, F. A. Martynenko
Within the framework of the quark model and the variational method, the bound states of four heavy quarks (tetraquarks) are investigated. The basis variational wave functions are chosen in the Gaussian form. The matrix elements of the Hamiltonian are calculated analytically. Numerical calculation of the energy levels of tetraquarks is performed using a program in the Matlab system. Hyperfine structure of the spectrum is calculated. To increase the accuracy of the calculation, relativistic corrections are taken into account.
在夸克模型和变分法的框架内,研究了四个重夸克(四夸克)的边界态。基础变分波函数选择高斯形式。哈密顿的矩阵元素是通过分析计算得到的。四夸克能级的数值计算使用 Matlab 系统中的程序进行。还计算了频谱的超细结构。为了提高计算的准确性,还考虑了相对论修正。
13. Scattering Entanglement Entropy and Its Implications for Electroweak Phase Transitionsid:2505.06001:id在线阅读
Jia Liu, Masanori Tanaka, Xiao-Ping Wang, Jing-Jun Zhang, Zifan Zheng
We investigate the connection between the entanglement entropy in scattering processes and the dynamics of electroweak phase transitions. Recent work has shown that the scattering entanglement entropy can provide new insight into Standard Model parameters. In this study, we propose that the maximum of the entanglement entropy in scattering amplitudes may serve as a diagnostic for first-order electroweak phase transitions in the early universe. We analyze a simplified extension of the Standard Model consisting of the Higgs boson $h$ coupled to $O(N)$ real singlet scalars $S$ via the Higgs portal coupling $\lambda_{hS}$. By explicitly calculating the maximum entanglement entropy, we demonstrate that it grows with increasing $\lambda_{hS}$, and that both first-order and strong first-order electroweak phase transitions are favored in regions of parameter space with large maximum entropy. Our results suggest that entanglement-based observables may encode meaningful information about the underlying dynamics of electroweak symmetry breaking and provide a novel perspective on phase transition phenomena.
我们研究了散射过程中的纠缠熵与电弱相变动力学之间的联系。最近的研究表明,散射纠缠熵可以为标准模型参数提供新的见解。在本研究中,我们提出散射振幅中纠缠熵的最大值可以作为早期宇宙一阶电弱相变的诊断指标。我们分析了标准模型的一个简化扩展,它由希格斯玻色子$h$通过希格斯门耦合$\lambda_{hS}$与$O(N)$实单子标量$S$耦合组成。通过明确计算最大纠缠熵,我们证明它随着$\lambda_{hS}$的增加而增长,并且在具有大最大熵的参数空间区域,一阶和强一阶电弱相变都是有利的。我们的研究结果表明,基于纠缠的观测指标可能会编码有关电弱对称破缺底层动力学的有意义信息,并为相变现象提供了一个新的视角。
14. pNGB Higgs Naturalness at a Tipping Pointid:2505.06052:id在线阅读
Matthew McCullough, Adriana Menkara, Ennio Salvioni
In scenarios where the Higgs is viewed as a pseudo Nambu-Goldstone boson (pNGB) the question of naturalness finds itself, from a phenomenological perspective, at a tipping point between direct searches and precision. If, by the end of the High-Luminosity LHC operation, all experimental results were to remain consistent with the Standard Model, precision Higgs coupling measurements will begin to drive the naturalness tension. To illustrate this from a fresh perspective we construct a maximally natural `Kitchen Sink' model, throwing into the mix three approaches to symmetry-based naturalness: Supersymmetry, Twin Higgs, and pNGB Higgs models with a Gegenbauer potential. In other words, we build a `Supersymmetric Gegenbauer's Twin' model. This model not only maximises naturalness, at least from a technical perspective, but can also interpolate between all three ingredients smoothly, revealing the interplay between direct exploration and precision. Implications for FCC-ee and FCC-hh are discussed.
在希格斯粒子被视为伪南布-金石玻色子(pNGB)的情况下,从现象学的角度来看,自然性问题本身就处于直接搜索和精确度之间的临界点。如果到高亮度大型强子对撞机运行结束时,所有实验结果都与标准模型保持一致,那么精确的希格斯耦合测量将开始推动自然性的紧张关系。为了从一个全新的角度说明这一点,我们构建了一个最大自然性的 "厨房水槽 "模型,将三种基于对称性的自然性方法融入其中:超对称、双希格斯和具有格根鲍尔势的 pNGB 希格斯模型。换句话说,我们建立了一个 "超对称格根鲍尔孪生模型"。至少从技术角度看,这个模型不仅最大限度地保持了自然性,而且还能在所有三种成分之间顺利插值,揭示了直接探索与精确性之间的相互作用。本文讨论了 FCC-ee 和 FCC-hh 的意义。
15. How to tame penguins: Advancing to high-precision measurements of $ϕ_d$ and $ϕ_s$id:2505.06102:id在线阅读
Kristof De Bruyn, Robert Fleischer, Eleftheria Malami
The complex phases $\phi_d$ and $\phi_s$, associated with the mixing between neutral $B_q^0$ and $\bar B_q^0$ mesons ($q\in\{d,s\}$), are key observables to test the Standard Model and search for contributions from new physics. They are conventionally determined from the measurements of mixing-induced CP violation in the decays $B_d^0\to J/\psi K^0$, $B_s^0\to J/\psi\phi$ and $B_s^0\to D_s^+D_s^-$. To reach the highest possible precision on $\phi_d$ and $\phi_s$, it is crucial that corrections from next-to-leading order effects - primarily associated with penguin decay topologies - are accounted for. The strategy adopted in this paper uses the $SU(3)$ flavour symmetry of QCD to relate the unknown contributions from penguin topologies to their counterparts in suitably-chosen control modes, where their effects are enhanced. Utilising new CP asymmetry measurements from LHCb on the decays $B_s^0\to D_s^+D_s^-$, $B_d^0\to D^+D^-$, $B^+\to J/\psi K^+$ and $B^+\to J/\psi\pi^+$, as well as from Belle-II on the decay $B_d^0\to J/\psi\pi^0$, we present the current state-of-the-art picture on controlling the penguin contributions and extract $\phi_d$ and $\phi_s$ from the corresponding observables. We explore the prospects for the end of the Belle-II and HL-LHC flavour physics programmes, and demonstrate the importance of measuring the control modes with future data.
与中性$B_q^0$和$bar B_q^0$介子($q\in\{d,s\}$)之间的混合相关的复相$\phi_d$和$\phi_s$是检验标准模型和寻找新物理贡献的关键观测指标。要想在 $\phi_d$ 和 $\phi_s$ 上达到尽可能高的精度,关键是要考虑到次导阶效应的修正--主要是与企鹅衰变拓扑相关的修正。本文采用的策略是利用 QCD 的 $SU(3)$ 味对称性,将企鹅拓扑的未知贡献与它们在适当选择的控制模式中的对应效应联系起来,在控制模式中,企鹅拓扑的效应会增强。利用LHCb对衰变$B_s^0\to D_s^+D_s^-$、$B_d^0\to D^+D^-$、$B^+\to J/\psi K^+$和$B^+\to J/\psi/pi^+$以及Belle-II对衰变$B_d^0\to J/\psi/pi^0$的新的CP不对称测量、我们介绍了当前控制企鹅贡献的最新情况,并从相应的观测数据中提取了 $\phi_d$ 和 $\phi_s$ 。我们探讨了Belle-II和HL-LHC味道物理计划结束的前景,并证明了用未来数据测量控制模式的重要性。
16. Chiral interactions, chiral states and "chiral neutrino oscillations"id:2505.06116:id在线阅读
A. Yu. Smirnov
In vacuum the ``chiral neutrino oscillations'', i.e. the periodic transitions between the left- and right-handed states do not occur. The produced state differs from the chiral component that appear in the Lagrangian of interactions and should be computed for each specific process. The phase difference between components of a produced neutrino is space-time independent. This neutrino state consists of only positive energy solutions of the Dirac equation and therefore the energy splitting $2E_\nu$ between the components with different helicities that would drive the chiral oscillations does not exist. Consideration in terms of neutrino propagators leads to the same conclusion. The situation is similar for the Majorana neutrinos and in the presence of flavor mixing. However, oscillations of the neutrino states produced in the chiral interactions are possible in matter with the length determined by the matter potential. Description of oscillations in terms of amplitudes of production and detection is elaborated that does not lead to any misconception. In the expanding Universe the relic neutrinos adiabatically convert to equal number densities of the left and right handed components.
在真空中,"手性中微子振荡';';",即左手态和右手态之间的周期性转变不会发生。产生的状态不同于相互作用拉格朗日中出现的手性分量,应针对每个特定过程进行计算。产生的中微子各分量之间的相位差与时空无关。这种中微子态仅由狄拉克方程的正能量解组成,因此,驱动手性振荡的不同螺旋分量之间的能量分裂 2E_\nu$ 并不存在。从中微子传播者的角度考虑也会得出同样的结论。对于马约拉纳中微子来说,在存在味道混合的情况下,情况也是类似的。然而,在手性相互作用中产生的中微子态的振荡在物质中是可能的,其长度由物质势决定。从产生和探测振幅的角度对振荡进行了详细描述,不会导致任何误解。在不断膨胀的宇宙中,遗迹中微子绝热地转化为数量密度相等的左右手成分。
17. Constraints to Lorentz violation and ultrahigh-energy electrons in D-foamy space-timesid:2505.06121:id在线阅读
Chengyi Li, Bo-Qiang Ma
We entertain the constraints that the absence of vacuum Cherenkov radiation of ultrahigh-energy electrons inferred from LHAASO observations of the Crab Nebula can impose on generic models in which Lorentz symmetry of the particle vacuum is violated, as established by some recent studies in \href{this https URL}{\emph{Phys. Lett. B} {\bf 829} (2022) 137034}; \href{this https URL}{{\bf 835} (2022) 137536}; \href{this https URL}{\emph{Phys. Rev. D} {\bf108} (2023) 063006}. We demonstrate in the present paper, that implementing a phenomenological approach to the Lorentz violation, the rates of this vacuum process are substantial such that one is justified in deriving bounds on the violation scales from simple threshold analysis just as these works did. Albeit such results are likely effective then, they do not apply in the same form among scenarios. Specifically, we show that these Cherenkov constraints are naturally evaded in models of space-time foam inspired from~(supercritical) string theory, involving D-branes as space-time defects in a brane-world scenario, in which subluminous energy-dependent refractive indices of light have been suggested. We examine here two specific foam situations and find for both cases~(though, for different reasons) the potentiality that charged quanta such as electrons do \emph{not} radiate as they pass through the gravitational vacuum `medium' despite moving faster than photons.
我们讨论了从蟹状星云的LHAASO观测中推断出的超高能电子的切伦科夫真空辐射的缺失可能对粒子真空的洛伦兹对称性被违反的一般模型施加的约束,正如最近在\href{this https URL}{\emph{Phys. Lett.B} {\bf 829} (2022) 137034}; \href{this https URL}{{\bf 835} (2022) 137536}; \href{this https URL}{{emph{Phys.}{\bf108} (2023) 063006}。我们在本文中证明,用现象学的方法来处理洛伦兹违反,这种真空过程的速率是非常可观的,因此我们有理由像这些著作一样,从简单的阈值分析中推导出违反尺度的边界。尽管这样的结果可能是有效的,但它们并不能以同样的形式适用于各种情况。具体地说,我们展示了这些切伦科夫约束在受~(超临界)弦理论启发的时空泡沫模型中被自然地回避了,这些模型涉及作为乙烯世界情景中时空缺陷的D-膜,在这种情景中,光的折射率被认为是亚光速的能量依赖性折射率。我们在这里研究了两种具体的泡沫情况,发现在这两种情况下~(尽管原因不同),电子等带电量子在通过引力真空 "介质 "时,尽管比光子移动得更快,但并不辐射。
18. Mechanical form factors and densities of non-relativistic fermionsid:2505.06135:id在线阅读
Adam Freese
The hadron physics community has been actively debating the interpretation of so-called mechanical properties of hadrons. Non-relativistic quantum-mechanical systems like the hydrogen atom have been appealed to in these debates as analogies. Since such appeals are likely to continue, it is important to have Galilei-covariant expressions for matrix elements of the energy-momentum tensor. In this work, I obtain Galilei-covariant breakdowns of such matrix elements into mechanical form factors, with a special focus on spin-half states. I additionally study the spatial densities associated with these form factors, using the pilot wave interpretation to guide their breakdown into contributions from internal structure and from quantum-mechanical effects such as wave packet dispersion. For completeness, I also obtain non-relativistic Breit frame densities.
强子物理学界一直在积极讨论如何解释强子的所谓机械特性。在这些争论中,氢原子等非相对论量子力学系统被当作类比对象。由于这种呼吁很可能会继续下去,因此为能量-动量张量的矩阵元素提供伽利略协变量表达式是非常重要的。在这项研究中,我获得了将这些矩阵元素分解为力学形式因子的伽利略-协变量,并特别关注自旋半态。此外,我还研究了与这些形式因子相关的空间密度,利用先导波解释将其分解为内部结构贡献和量子力学效应(如波包色散)贡献。为了完整起见,我还获得了非相对论布赖特框架密度。
19. Revisiting the connection of baryon number, lepton number, and operator dimensionid:2505.06172:id在线阅读
Julian Heeck, Diana Sokhashvili
The effects of heavy new particles beyond the Standard Model can be conveniently captured through higher-dimensional effective operators. As noted long ago by Weinberg, the amount of baryon and lepton number an operator can carry is intricately connected to its mass dimension. We derive an improved inequality for this connection and compare it to explicit operator constructions up to mass dimension 25. For the effective field theory of Standard Model plus right-handed neutrinos, our relationship is even an equality up to high mass dimension.
标准模型之外的新重型粒子的影响可以通过高维有效算子方便地捕捉到。正如温伯格早就指出的,算子所能携带的重子和轻子数量与其质量维度有着错综复杂的联系。我们针对这种联系推导出了一个改进的不等式,并将其与质量维度高达 25 的显式算子构造进行了比较。对于标准模型加右手中微子的有效场论,我们的关系甚至在质量维度较高时也是相等的。
20. An Effective Theory for Higgs Inflationid:2505.06197:id在线阅读
A. Tronconi, G. Venturi
The generation of large curvature perturbations associated with the production of primordial black holes is studied in the context of a Higgs inflaton. To enable this amplification, we consider an inflationary model in which the tree-level action for gravity and the Standard Model Higgs is modified by quantum corrections, described by a series of higher-dimension operators. Finally within a minimal EFT framework, we present two viable models in which the spectrum of curvature perturbations generated by the Higgs field is consistent with CMB observations and can lead to the formation of primordial black holes in the asteroid mass range, potentially accounting for the entirety of dark matter.
我们在希格斯膨胀子的背景下研究了与原始黑洞产生相关的大曲率扰动的产生。为了实现这种放大,我们考虑了一个膨胀模型,在这个模型中,引力和标准模型希格斯的树级作用被一系列高维算子描述的量子修正所修正。最后,在一个最小 EFT 框架内,我们提出了两个可行的模型,其中希格斯场产生的曲率扰动谱与 CMB 观察结果一致,并能导致小行星质量范围内原始黑洞的形成,有可能解释暗物质的全部。
21. Axion optical induction of antiferromagnetic orderid:2303.05451:id在线阅读
Jian-Xiang Qiu, Christian Tzschaschel, Junyeong Ahn, Anyuan Gao, Houchen Li, Xin-Yue Zhang, Barun Ghosh, Chaowei Hu, Yu-Xuan Wang, Yu-Fei Liu, Damien Bérubé, Thao Dinh, Zhenhao Gong, Shang-Wei Lien, Sheng-Chin Ho, Bahadur Singh, Kenji Watanabe, Takashi Taniguchi, David C. Bell, Hai-Zhou Lu, Arun Bansil, Hsin Lin, Tay-Rong Chang, Brian B. Zhou, Qiong Ma, Ashvin Vishwanath, Ni Ni, Su-Yang Xu
Using circularly-polarized light to control quantum matter is a highly intriguing topic in physics, chemistry and biology. Previous studies have demonstrated helicity-dependent optical control of spatial chirality and magnetization $M$. The former is central for asymmetric synthesis in chemistry and homochirality in bio-molecules, while the latter is of great interest for ferromagnetic spintronics. In this paper, we report the surprising observation of helicity-dependent optical control of fully-compensated antiferromagnetic (AFM) order in 2D even-layered MnBi$_2$Te$_4$, a topological Axion insulator with neither chirality nor $M$. We further demonstrate helicity-dependent optical creation of AFM domain walls by double induction beams and the direct reversal of AFM domains by ultrafast pulses. The control and reversal of AFM domains and domain walls by light helicity have never been achieved in any fully-compensated AFM. To understand this optical control, we study a novel type of circular dichroism (CD) proportional to the AFM order, which only appears in reflection but is absent in transmission. We show that the optical control and CD both arise from the optical Axion electrodynamics, which can be visualized as a Berry curvature real space dipole. Our Axion induction provides the possibility to optically control a family of $\mathcal{PT}$-symmetric AFMs such as Cr$_2$O$_3$, CrI$_3$ and possibly novel states in cuprates. In MnBi$_2$Te$_4$, this further opens the door for optical writing of dissipationless circuit formed by topological edge states.
利用圆偏振光控制量子物质是物理学、化学和生物学领域一个非常有趣的课题。之前的研究已经证明了对空间手性和磁化 $M$ 的螺旋度依赖性光学控制。前者是化学中不对称合成和生物分子中同手性的核心,而后者则是铁磁自旋电子学的重要兴趣所在。在本文中,我们报告了在二维偶层 MnBi$_2$Te$_4$--一种既没有手性也没有 $M$ 的拓扑轴心绝缘体--中观察到的全补偿反铁磁(AFM)秩序的螺旋度依赖性光学控制的惊人现象。我们进一步证明了通过双感应光束和超快脉冲直接逆转AFM畴墙的依赖螺旋的光学创造。在任何完全补偿的原子力显微镜中,都从未实现过通过光的螺旋度来控制和逆转原子力显微镜畴和畴墙。为了理解这种光学控制,我们研究了一种与原子力显微镜阶次成比例的新型圆二色性(CD),它只在反射中出现,而在透射中不存在。我们的研究表明,光学控制和圆二色性都源于光学轴向电动力学,而轴向电动力学可视化为贝里曲率实空间偶极子。我们的轴向感应为光学控制一系列$\mathcal{PT}$对称原子力金属提供了可能,如Cr$_2$O$_3$、CrI$_3$以及铜酸盐中可能存在的新状态。在 MnBi$_2$Te$_4$ 中,这进一步为拓扑边缘态形成的无耗散电路的光写入打开了大门。
22. Di-nucleons do not form bound states at heavy pion massid:2505.05547:id在线阅读
John Bulava, M.A. Clark, Arjun S. Gambhir, Andrew D. Hanlon, Ben Hörz, Bálint Joó, Christopher Körber, Ken McElvain, Aaron S. Meyer, Henry Monge-Camacho, Colin Morningstar, Joseph Moscoso, Amy Nicholson, Fernando Romero-López, Ermal Rrapaj, Andrea Shindler, Sarah Skinner, Pavlos M. Vranas, André Walker-Loud
We perform a high-statistics lattice QCD calculation of the low-energy two-nucleon scattering amplitudes. In order to address discrepancies in the literature, the calculation is performed at a heavy pion mass in the limit that the light quark masses are equal to the physical strange quark mass, $m_\pi = m_K \simeq 714 $ MeV. Using a state-of-the-art momentum space method, we rule out the presence of a bound di-nucleon in both the isospin 0 (deuteron) and 1 (di-neutron) channels, in contrast with many previous results that made use of compact hexaquark creation operators. In order to diagnose the discrepancy, we add such hexaquark interpolating operators to our basis and find that they do not affect the determination of the two-nucleon finite volume spectrum, and thus they do not couple to deeply bound di-nucleons that are missed by the momentum-space operators. Further, we perform a high-statistics calculation of the HAL QCD potential on the same gauge ensembles and find qualitative agreement with our main results. We conclude that two-nucleons do not form bound states at heavy pion masses and that previous identification of deeply bound di-nucleons must have arisen from a misidentification of the spectrum from off-diagonal elements of a correlation function.
我们对低能双核散射振幅进行了高统计网格 QCD 计算。为了解决文献中的差异,计算是在轻夸克质量等于物理奇异夸克质量($m_\pi = m_K \simeq 714 $ MeV)的极限下的重先驱质量下进行的。利用最先进的动量空间方法,我们排除了等空0(氘核)和1(二中子)通道中存在束缚二核的可能性,这与之前利用紧凑的六夸克创造算子得出的许多结果截然不同。为了诊断这种差异,我们将这种六夸克内插算子添加到我们的基础中,发现它们并不影响双核有限体积谱的确定,因此它们不会与动量空间算子遗漏的深度束缚二核耦合。此外,我们在相同的量规集合上对 HAL QCD 势进行了高统计计算,发现与我们的主要结果在质量上是一致的。我们的结论是,双核子在重先驱质量下不会形成束缚态,而且以前对深度束缚二核子的识别一定是源于对相关函数非对角元素频谱的错误识别。
23. Multipositivity Boundsid:2505.05553:id在线阅读
Clifford Cheung, Grant N. Remmen
Lorentz invariance, unitarity, and causality enforce powerful constraints on the theory space of physical scattering amplitudes. However, virtually all efforts in this direction have centered on the very simplest case of four-point scattering. In this work, we derive an infinite web of "multipositivity bounds" that nonlinearly constrain all tree-level higher-point scattering amplitudes under similarly minimal assumptions. Our construction rules out several deformations of the string and implies mixed-multiplicity bounds on the Wilson coefficients of planar effective field theories. Curiously, an infinite class of multipositivity bounds is exactly saturated by the amplitudes of the open string.
洛伦兹不变性、单位性和因果性对物理散射振幅的理论空间施加了强大的约束。然而,几乎所有这方面的努力都集中在最简单的四点散射情况上。在这项工作中,我们推导出了一个无穷的"多正性约束"网,在类似的最小假设条件下,非线性地约束了所有树级高点散射振幅。我们的构造排除了弦的几种变形,并隐含了平面有效场理论威尔逊系数的混合多重性约束。奇怪的是,一个无限类的多重性约束正好被开放弦的振幅所饱和。
24. Measurement of medium-induced acoplanarity in central Au-Au and pp collisions at $\sqrt{s_{\rm NN}}=200$ GeV using direct-photon+jet and $π^{0}$+jet correlationsid:2505.05789:id在线阅读
The STAR Collaboration
The STAR Collaboration reports measurements of acoplanarity using semi-inclusive distributions of charged-particle jets recoiling from direct photon and $\pi^{0}$ triggers, in central Au-Au and pp collisions at $\sqrt{s_{\rm NN}}=200$ GeV. Significant medium-induced acoplanarity broadening is observed for large but not small recoil jet resolution parameter, corresponding to recoil jet yield enhancement up to a factor of $\approx20$ for trigger-recoil azimuthal separation far from $\pi$. This phenomenology is indicative of the response of the Quark-Gluon Plasma to excitation, but not the scattering of jets off of its quasiparticles. The measurements are not well-described by current theoretical models which incorporate jet quenching.
STAR协作组报告了在$\sqrt{s_\{rm NN}}=200$ GeV的中心金-金和pp对撞中,利用直接光子和$\pi^{0}$触发器反冲的带电粒子射流的半包围分布对尖面性的测量结果。在反冲射流分辨率参数大而不小的情况下,可以观察到显著的介质诱导的尖平面展宽,在触发-反冲方位角分离远离$\pi$的情况下,相应的反冲射流产率增强可达$\approx20$。这一现象表明夸克-胶子等离子体对激发的响应,而不是其准粒子的射流散射。目前包含射流淬火的理论模型并不能很好地描述这些测量结果。
25. Spectroscopic Supermassive Dark Star candidatesid:2505.06101:id在线阅读
Cosmin Ilie, Sayed Shafaat Mahmud, Jillian Paulin, Katherine Freese
Dark Stars, i.e. early stars composed almost entirely of hydrogen and helium but powered by Dark Matter, could form in zero metallicity clouds located close to the center of high redshift Dark Matter halos. In 2023 three of us identified (in a PNAS work) the first three photometric Dark Star candidates: JADES-GS-z11-0, JADES-GS-z12-0, and JADES-GS-z13-0. We report here our results of a followup analysis based on available NIRSpec JWST data. We find that JADES-GS-z11-0 and JADES-GS-z-13-0 are spectroscopically consistent with a Dark Star interpretation. Moreover, we find two additional spectroscopic Dark Star candidates: JADES-GS-z14-0 and JADES-GS-z-14-1, with the former being the most distant luminous object ever observed. We furthermore identify a feature in its spectrum indicative of the smoking gun signature of Dark Stars: the He II$\lambda$1640 absorption line. In view ALMA's recent identification of a probable OIII nebular emission line in the spectrum of JADES-GS-z14-0, the simple interpretation of this object as an isolated Dark Star is unlikely. If both spectral features survive follow-up observations it would imply a Dark Star embedded in a metal rich environment, requiring theoretical refinements of the formation of evolution of Dark Stars, which in previous studies were assumed to form in isolation, without any companions.
暗星,即几乎完全由氢和氦组成但由暗物质驱动的早期恒星,可能形成于靠近高红移暗物质光环中心的零金属度云中。2023 年,我们中的三人(在《美国科学院院刊》(PNAS)的一篇论文中)确定了首批三颗测光暗星候选者:JADES-GS-z11-0、JADES-GS-z12-0和JADES-GS-z13-0。我们在此报告基于现有 NIRSpec JWST 数据的后续分析结果。我们发现JADES-GS-z11-0和JADES-GS-z-13-0在光谱学上与暗星的解释是一致的。此外,我们还发现了另外两颗候选光谱暗星:JADES-GS-z14-0和JADES-GS-z-14-1,前者是迄今观测到的最遥远的发光天体。此外,我们还在它的光谱中发现了暗星的烟枪特征:He II$\lambda$1640 吸收线。鉴于ALMA最近在JADES-GS-z14-0的光谱中发现了一条可能的OIII星云发射线,简单地把这个天体解释为一颗孤立的暗星是不太可能的。如果这两个光谱特征都能在后续观测中继续存在,那就意味着一颗暗星被嵌入了一个富含金属的环境中,这就需要从理论上完善暗星的形成和演化过程,而在以前的研究中,暗星被假定是孤立形成的,没有任何伴星。
26. Revealing the nature of ultra-long period objects with space-based gravitational-wave interferometersid:2505.06125:id在线阅读
Arthur G. Suvorov, Clara Dehman, José A. Pons
A few members of the recently-discovered class of ultra-long period objects have been identified as binaries with white-dwarf primaries. In most cases however, electromagnetic data are inconclusive and isolated magnetars remain a viable candidate. If the pulsation period matches that of the orbit though -- as is the case for ILT J1101+5521 and GLEAM-X J0704-37 -- several of these elusive radio transients should be gravitational-wave bright in the mHz band. Space-based interferometers could thus be used to provide independent constraints on their nature. We quantify the signal-to-noise ratio for the known systems, assuming they are compact binaries, and show that a few should be detectable with only a few months of data folding. Astrophysical implications for (non-)detections are discussed.
最近发现的几类超长周期天体中,有几个已经被确定为带有白矮星主星的双星。然而在大多数情况下,电磁数据并不能给出结论,孤立的磁星仍然是一个可行的候选者。如果脉动周期与轨道周期一致--ILT J1101+5521 和 GLEAM-X J0704-37 就是这种情况--那么这些难以捉摸的射电瞬变天体中的几个在 mHz 波段应该是引力波亮点。因此,天基干涉仪可以用来对它们的性质提供独立的约束。我们对已知系统的信噪比进行了量化(假设它们是紧凑型双星),并表明只需折叠几个月的数据就能探测到一些系统。讨论了(非)探测到的天体物理学影响。
27. Magnetar field dynamics shaped by chiral anomalies and helicityid:2505.06196:id在线阅读
Clara Dehman, José A. Pons
The chiral magnetic effect (CME), a macroscopic manifestation of the quantum chiral anomaly, induces currents along magnetic field lines, facilitating mutual conversion between chiral asymmetry and magnetic helicity. Although the finite electron mass suppresses chiral asymmetry through spin-flip processes, we demonstrate that the CME remains effective and plays a significant role in the magnetic field evolution of magnetars. The magnetic helicity acts as a persistent internal source of chiral asymmetry, which mediates the redistribution of magnetic energy across spatial scales, without requiring an external energy source. Focusing on the neutron star crust, we show that this mechanism reshapes the magnetic field configuration inherited at birth and, within a hundred years, amplifies both toroidal and poloidal large-scale dipolar components (relevant for spin-down) up to $10^{14}$ G at the expense of small-scale structures. Our results offer a microphysical mechanism, alternative to traditional hydrodynamic dynamo models, establishing a new framework for understanding magnetar field dynamics.
手性磁效应(CME)是量子手性反常现象的宏观表现,它沿着磁场线诱导电流,促进手性不对称和磁螺旋之间的相互转换。虽然有限电子质量通过自旋翻转过程抑制了手性不对称,但我们证明了 CME 仍然有效,并在磁星的磁场演化中发挥着重要作用。磁螺旋作为手性不对称的持续内部来源,介导了磁能在空间尺度上的重新分配,而不需要外部能量源。我们以中子星外壳为研究对象,展示了这种机制重塑了诞生时继承的磁场构型,并在一百年内放大了环形和极坐标大尺度偶极分量(与自旋下降有关)达10^{14}$ G,而牺牲了小尺度结构。我们的研究结果提供了一种微物理机制,替代了传统的流体动力学动力模型,为理解磁星场动力学建立了一个新框架。
28. Confirmation of the existence of an exotic state in the $πD$ systemid:2106.15391:id在线阅读
Eric B. Gregory, Feng-Kun Guo, Christoph Hanhart, Stefan Krieg, Thomas Luu
In recent years many candidates for states beyond the most simple realization of the quark model were found in various experiments around the world. However, so far no consensus exists on their structure, although there is strong evidence that at least some of those are dynamically generated from meson-meson interactions. In this Letter we provide an important missing piece from the theoretical side to prove that the lightest open charm strange and non-strange scalars $D_{s0}^*(2317)$ and $D_0^*$ as well as their axial-vector partner states can all be understood as emerging from the interactions between Goldstone bosons stemming from the spontaneous breaking of chiral symmetry and the ground state charmed mesons. For that purpose we exploit the flavor multiplet structure of the lightest open-charm positive-parity scalar states in an SU(3) symmetric lattice QCD simulation at large pion masses to establish that there exists a bound state in the flavor-sextet representation, which cannot emerge for quark-antiquark states but appears naturally for four-quark configurations. Moreover, we find repulsion in the $[15]$ representation and thus no single-particle state in this representation exists, falsifying the expectation for tetraquark models. The findings establish the pattern predicted for the interactions of Goldstone bosons with $D$ mesons from chiral symmetry and the paradigm of the lowest-lying positive-parity charmed mesons as dynamically generated states.
近年来,在世界各地的各种实验中发现了许多超越夸克模型最简单实现的候选态。然而,尽管有强有力的证据表明其中至少有一些是介子-介子相互作用动态生成的,但迄今为止人们对它们的结构还没有达成共识。在这封信中,我们从理论方面提供了一个重要的缺失片段,证明最轻的开放粲奇异和非奇异标量 $D_{s0}^*(2317)$ 和 $D_0^*$ 以及它们的轴向矢量伙伴态都可以理解为产生于手性对称自发破缺产生的金石玻色子与基态粲介子之间的相互作用。为此,我们利用大先锋质量下 SU(3) 对称晶格 QCD 模拟中最轻的开粲正奇偶性标量态的味道多重结构,确定在味道六元表征中存在一种束缚态,这种束缚态无法出现在夸克-反夸克态中,但会自然地出现在四夸克构型中。此外,我们还发现了 $[15]$ 表征中的斥力,因此在这个表征中不存在单粒子态,从而证伪了四夸克模型的预期。这些发现确立了根据手性对称性预测的金石玻色子与 $D$ 介子的相互作用模式,以及最低正奇偶性粲介子作为动态生成态的范式。
29. Dark Matter-Induced Low-Mass Gap Black Hole Echoing LVK Observationsid:2404.04827:id在线阅读
Shuailiang Ge, Yuxin Liu, Jing Shu, Yue Zhao
The recent detection of gravitational waves from a binary merger involving a potential low-mass gap black hole (LMBH) by LIGO-Virgo-KAGRA (LVK) Collaboration motivates investigations into mechanisms beyond conventional stellar evolution theories to account for their existence. We study a mechanism in which dark matter (DM), through its capture and accumulation inside main sequence stars, induces the formation of black holes within the mass range of $[3, 5]M_\odot$. We examine the distribution of these LMBHs as a function of galaxy halo mass, particularly when paired with neutron stars. This gives a distinct signature that can be tested with future gravitational wave observations. We find that a viable portion of the DM parameter space predicts a merger rate of such binaries consistent with LVK observations.
最近,LIGO-Virgo-KAGRA(LVK)合作组织探测到了双星合并产生的引力波,其中涉及一个潜在的低质量间隙黑洞(LMBH),这促使我们研究传统恒星演化理论之外的机制,以解释它们的存在。我们研究了这样一种机制:暗物质(DM)通过在主序星内部的捕获和积累,诱发了质量范围在$[3, 5]M_\odot$内的黑洞的形成。我们研究了这些黑洞的分布与星系晕质量的函数关系,尤其是与中子星配对时。这给出了一个明显的特征,可以用未来的引力波观测来检验。我们发现,DM参数空间的一个可行部分预言了这类双星的合并率与LVK观测结果一致。
30. Proton-box contribution to $a_μ^{\rm{HLbL}}$id:2411.07115:id在线阅读
Emilio J. Estrada, Juan Manuel Márquez, Diego Portillo-Sánchez, Pablo Roig
We analyze the proton$\text{-}$box contribution to the hadronic light$\text{-}$by$\text{-}$light part of the muon's anomalous magnetic moment, which is the first reported baryonic contribution to this piece. We follow the quark$\text{-}$loop analysis, incorporating the relevant data$\text{-}$driven and lattice proton form factors. Although the heavy mass expansion would yield a contribution of $\mathcal{O}(10^{-10})$, the damping of the form factors in the regions where the kernel peaks, explains our finding $a_{\mu}^{\rm{p-box}}=1.82 (7)\times 10^{-12}$, two orders of magnitude smaller than the forthcoming uncertainty on the $a_{\mu}$ measurement and on its Standard Model prediction.
我们分析了质子$text{-}盒对μ介子'反常磁矩的强子轻$text{-}-$by$text{-}轻部分的贡献,这是首次报道的重子对这部分的贡献。我们沿用了夸克环的分析方法,纳入了相关的数据和晶格质子形式因子。尽管重质量扩展会产生$\mathcal{O}(10^{-10})$的贡献,但形式因子在核峰值区域的阻尼解释了我们的发现:$a_{\mu}^{\rm{p-box}}=1.82 (7)/times 10^{-12}$,比即将到来的$a_{\mu}$测量及其标准模型预测的不确定性小两个数量级。
31. Machine Learning Neutrino-Nucleus Cross Sectionsid:2412.16303:id在线阅读
Daniel C. Hackett, Joshua Isaacson, Shirley Weishi Li, Karla Tame-Narvaez, Michael L. Wagman
Neutrino-nucleus scattering cross sections are critical theoretical inputs for long-baseline neutrino oscillation experiments. However, robust modeling of these cross sections remains challenging. For a simple but physically motivated toy model of the DUNE experiment, we demonstrate that an accurate neural-network model of the cross section -- leveraging Standard Model symmetries -- can be learned from near-detector data. We then perform a neutrino oscillation analysis with simulated far-detector events, finding that the modeled cross section achieves results consistent with what could be obtained if the true cross section were known exactly. This proof-of-principle study highlights the potential of future neutrino near-detector datasets and data-driven cross-section models.
中微子-核散射截面是长基线中微子振荡实验的关键理论输入。然而,这些截面的稳健建模仍具有挑战性。对于 DUNE 实验的一个简单但具有物理动机的玩具模型,我们证明了可以从近探测器数据中学习到精确的神经网络截面模型--利用标准模型对称性。然后,我们用模拟的远探测器事件进行了中微子振荡分析,发现建模的截面结果与准确知道真实截面时的结果一致。这项原理验证研究凸显了未来中微子近探测器数据集和数据驱动截面模型的潜力。
32. Very Special Relativity in Accelerated Frames: Non-relativistic Effects in Gravitational Spectroscopy of Ultracold Neutronsid:2501.06558:id在线阅读
Alessandro Santoni, Enrique Muñoz, Hartmut Abele, Benjamin Koch
In this paper, we investigate the phenomenology of fermionic systems in uniform gravitational fields within the framework of Very Special Relativity (VSR). We focus on the case of gravitational spectroscopy with ultracold neutrons, explored in experiments like \emph{q}\textsc{Bounce}. Calculating the leading ($c^0$) and next-to-leading ($c^{-1}$) order corrections to the non-relativistic Hamiltonian in an accelerated frame, we obtain the perturbed fermionic energy spectrum. At leading order, we do not find any modifications except for a trivial mass shift, thus preserving the equivalence between inertial and gravitational mass and particle-antiparticle sectors. The next-to-leading order corrections, instead, introduce time-dependent anisotropic contributions depending on the preferred spatial direction in VSR, and can then be used to probe novel Lorentz-violating signatures. Taking \emph{q}\textsc{Bounce} sensitivity as a benchmark, we derive a first rough constraint for the neutron VSR parameter. Finally, we suggest alternative spin-flipping setups to better probe VSR effects and foresee potential future research directions.
在本文中,我们在非常狭义相对论(VSR)的框架内研究了均匀引力场中费米子系统的现象学。我们把重点放在超冷中子的引力光谱学上,在 \emph{q}\textsc{Bounce}等实验中进行了探索。通过计算加速框架下非相对论哈密顿的前导($c^0$)和次前导($c^{-1}$)阶修正,我们得到了扰动费米子能谱。在先导阶,除了微不足道的质量偏移之外,我们没有发现任何修正,因此保持了惯性质量和引力质量以及粒子-反粒子扇区之间的等价性。次先导阶修正反而引入了与时间相关的各向异性贡献,这取决于VSR的优先空间方向,然后可以用来探测新的违反洛伦兹的特征。以\emph{q}\textsc{Bounce}灵敏度为基准,我们得出了中子VSR参数的第一个粗略约束。最后,我们建议采用其他自旋翻转设置来更好地探测VSR效应,并展望了未来潜在的研究方向。
33. Entering the overcritical regime of nonlinear Breit-Wheeler pair production in collisions of bremsstrahlung $γ$-rays and superintense, tightly focused laser pulsesid:2501.08790:id在线阅读
I. Elsner, A. Golub, S. Villalba-Chávez, C. Müller
Near-future high-intensity lasers offer prospects for the observation of nonlinear Breit-Wheeler pair production in an overcritical field regime, where the quantum nonlinearity parameter substantially exceeds unity. This experimentally yet unexplored scenario is envisaged here to be reached via the collision of a tightly focused laser pulse with high-energy bremsstrahlung photons. We calculate the achievable number of pairs in a range of laser intensities around 10$^{23}$ W/cm$^2$ and GeV-energies of the incident bremsstrahlung-generating electron beam. We investigate under which conditions the attenuation of the $\gamma$-beam due to the production process must be taken into account and how much the second generation of created pairs contributes to the total yield. In the considered interaction regime, where the local production rate grows rather moderately with higher field intensities, it is shown that the range of mostly contributing bremsstrahlung frequencies is generally very broad. For sufficiently large values of the quantum nonlinearity parameter, an optimum domain of frequencies emerges which is located far below the spectral endpoint. Furthermore, we show that it is beneficial for achieving the optimum pair yield to increase the interaction volume by a wider laser focus at the expense of decreased field intensity.
近未来的高强度激光器为观测超临界场机制下的非线性布赖特-维勒对产生提供了前景,在超临界场机制下,量子非线性参数大大超过了统一值。在此,我们设想通过高能轫致辐射光子与聚焦激光脉冲的碰撞来实现这种实验上尚未探索的情况。我们计算了在 10$^{23}$ W/cm$^2$ 左右的激光强度和入射轫致辐射电子束的 GeV 能量范围内可实现的光对数量。我们研究了在哪些条件下必须考虑产生过程导致的伽马射线衰减,以及第二代产生的电子对对总产率的贡献有多大。在所考虑的相互作用机制中,随着场强的增大,局部产生率的增长相当温和,这表明主要贡献轫致辐射频率的范围通常非常宽。在量子非线性参数值足够大的情况下,会出现一个最佳频率域,它远远低于频谱端点。此外,我们还证明,以降低场强为代价,通过扩大激光聚焦范围来增加相互作用体积,有利于获得最佳成对率。
34. Electromagnetic leptogenesis with light-heavy sterile neutrinosid:2501.13150:id在线阅读
Debasish Borah, Arnab Dasgupta
We propose a novel leptogenesis scenario utilising the two-body decay of heavy right handed neutrino (RHN) via the electromagnetic dipole operator. While the requirement of the standard model (SM) gauge invariance requires such dipole operator only at dimension-6 forcing the generation of non-zero CP asymmetry from three-body decay with two-loop corrections, we write down dimension-5 dipole operators involving heavy RHN $N_R$ and its lighter counterpart $\nu_R$. This allows the generation of lepton asymmetry in $\nu_R$ from two-body decay of heavy RHN which later gets transferred to left handed leptons via sizeable Yukawa coupling with a neutrinophilic Higgs doublet. The asymmetry in left handed leptons is then converted to baryon asymmetry via electroweak sphalerons. The lepton number violation by heavy RHN also induces a one-loop Majorana mass of $\nu_R$ rendering the light neutrinos to be Majorana fermions. While smallness of the Majorana mass of $\nu_R$ prevents additional sources or washout of lepton asymmetry, it also constrains the scale of leptogenesis. For $\mathcal{O}(10)$ TeV scale leptogenesis, this leads to additional sterile neutrinos lighter than a few keV with interesting implications for a variety of observables including neutrino oscillation, warm dark matter as well as effective degrees of freedom within reach of future cosmic microwave background experiments. Additionally, heavy RHN can lead to observable monochromatic photon signatures at terrestrial experiments.
我们提出了一种利用重右手中微子(RHN)通过电磁偶极子算子进行两体衰变的新型轻生成方案。虽然标准模型(SM)的规不变性要求这种偶极子算子只能在维度-6上产生非零CP不对称,但我们写下了涉及重RHN $N_R$及其轻对应物$\nu_R$的维度-5偶极子算子。这使得重RHN的二体衰变在$\nu_R$中产生轻子不对称,随后通过与中性希格斯双t的可观的尤卡娃耦合转移到左手轻子上。左手轻子的不对称性随后通过电弱闪子转化为重子不对称性。重RHN对轻轻子的轻子数违反也导致了$\nu_R$的一环马约拉纳质量,从而使轻中微子成为马约拉纳费米子。尽管$\nu_R$的马约拉纳质量较小,可以防止轻子不对称的额外来源或冲刷,但它也制约了轻子发生的尺度。对于$\mathcal{O}(10)$ TeV尺度的轻子发生,这会导致额外的轻于几KeV的不育中微子,这对包括中微子振荡、暖暗物质以及未来宇宙微波背景实验范围内的有效自由度在内的各种观测指标都会产生有趣的影响。此外,重中微子还能在地面实验中产生可观测到的单色光子特征。
35. Factorisation schemes for proton PDFsid:2501.18289:id在线阅读
Stéphane Delorme, Aleksander Kusina, Andrzej Siódmok, James Whitehead
Beyond leading-order, perturbative QCD requires a choice of factorisation scheme to define the parton distribution functions (PDFs) and hard-process cross-section. The modified minimal-subtraction ($\overline{\mathrm{MS}}$) scheme has long been adopted as the default choice due to its simplicity. Alternative schemes have been proposed with specific purposes, including, recently, PDF positivity and NLO parton-shower matching. In this paper we assemble these schemes in a common notation for the first time. We perform a detailed comparison of their features, both analytically and numerically, and estimate the resulting factorisation-scheme uncertainty for LHC phenomenology.
在前沿阶之外,微扰 QCD 需要选择一种因式分解方案来定义粒子分布函数(PDF)和硬过程截面。由于其简单性,修正的最小减法($overline{\mathrm{MS}}$)方案长期以来一直被作为默认选择。人们提出了具有特定目的的替代方案,包括最近提出的 PDF 正性和 NLO Parton-shower 匹配。在本文中,我们首次将这些方案集合在一个通用符号中。我们对它们的特点进行了详细的分析和数值比较,并估算了LHC现象学的因子化方案不确定性。
36. Monte Carlo simulation of GRB data to test Lorentz-invariance violationid:2504.15685:id在线阅读
Hanlin Song, Bo-Qiang Ma
Lorentz-invariance violation (LV) at energy scales approaching the Planck regime serves as a critical probe for understanding quantum gravity phenomenology. Astrophysical observations of gamma-ray bursts (GRBs) present a promising avenue for testing LV-induced spectral lag phenomena; however, interpretations are complicated by degeneracies between LV effects and intrinsic emission delays. This study systematically investigates three competing time delay models: Model A (LV delay combined with a constant intrinsic delay), Model B (energy-dependent intrinsic delay without LV), and Model C (LV delay combined with energy-dependent intrinsic delay). We utilize mock GRB datasets generated under distinct delay mechanisms and employ Bayesian parameter estimation on simulated observations of 10 GRBs. Our findings demonstrate that Model C consistently recovers input parameters across all datasets. In contrast, Models A and B struggle to reconcile data generated under alternative mechanisms, particularly when confronted with high-energy TeV photons from GRB 190114C and GRB 221009A. Our analysis confirms that the incorporation of energy-dependent intrinsic delays in Model C is essential for establishing robust LV constraints, effectively resolving prior ambiguities in the interpretation of multi-GeV and TeV photon emissions. The results validate Model C as a generalized framework for future LV searches, yielding a subluminal LV scale of \(E_{\rm LV} \simeq 3 \times 10^{17}\) GeV based on realistic datasets. These findings are consistent with earlier constraints derived from Fermi-LAT datasets. This work underscores the necessity for joint modeling of LV and astrophysical emission processes in next-generation LV studies utilizing observatories such as LHAASO and CTA.
在接近普朗克机制的能量尺度上的洛伦兹不变量违反(LV)是理解量子引力现象学的一个关键探针。对伽马射线暴(GRBs)的天体物理观测为测试 LV 引起的光谱滞后现象提供了一个很有前景的途径;然而,LV 效应与内在发射延迟之间的退行性使解释变得复杂。本研究系统地研究了三种相互竞争的时间延迟模型:模型 A(LV 延迟与恒定的本征延迟相结合)、模型 B(与能量有关的本征延迟,不含 LV)和模型 C(LV 延迟与与能量有关的本征延迟相结合)。我们利用在不同延迟机制下生成的模拟 GRB 数据集,并对 10 个 GRB 的模拟观测结果进行贝叶斯参数估计。我们的研究结果表明,模型 C 在所有数据集上都能一致地恢复输入参数。与此相反,模型 A 和模型 B 难以调和在其他机制下产生的数据,尤其是在面对来自 GRB 190114C 和 GRB 221009A 的高能 TeV 光子时。我们的分析证实,在模型 C 中纳入与能量相关的固有延迟对于建立稳健的 LV 约束至关重要,它可以有效地解决先前在解释多 GeV 和 TeV 光子发射时存在的模糊之处。结果验证了模型C是未来LV搜索的通用框架,基于现实数据集得出的亚流态LV尺度为\(E_\rm LV} \simeq 3 \times 10^{17}\) GeV。这些发现与先前从费米-LAT数据集得出的约束相一致。这项工作强调了在利用 LHAASO 和 CTA 等天文台进行下一代 LV 研究时对 LV 和天体物理发射过程进行联合建模的必要性。
37. Brazilian Report on Dark Matter 2024id:2504.16228:id在线阅读
I. F. M. Albuquerque, J. Alcaniz, A. Alves, J. Amaral, C. Bonifazi, H. A. Borges, S. Carneiro, L. Casarini, D. Cogollo, A. G. Dias, G. C. Dorsch, A. Esmaili, G. Gil da Silveira, C. Gobel, V. P. Gonçalves, A. S. Jesus, D. Hadjimichef, P. C. de Holanda, R.F.L. Holanda, E. Kemp, A. Lessa, A. Machado, M.V T. Machado, M. Makler, V. Marra, M. S. Mateus Junior, R. D. Matheus, P. G. Mercadante, A. A. Nepomuceno, R.M.P. Neves, C. Nishi, Y.M. Oviedo-Torres, N. Pinto, C. A. Pires, E. Polycarpo, F. S. Queiroz, T. Quirino, M. S. Rangel, P. Rebello Teles, D. C. Rodrigues, J. G. Rodrigues, P. S. Rodrigues da Silva, R. Rosenfeld, B. L. Sanchez-Vega, E. Segretto, R. Silva, D. R. da Silva, C. Siqueira, V. de Souza, S. Fonseca De Souza, T. R. F. P. Tomei, G. A. Valdiviesso, A. Viana, Y. Villamizar
One of the key scientific objectives for the next decade is to uncover the nature of dark matter (DM). We should continue prioritizing targets such as weakly-interacting massive particles (WIMPs), Axions, and other low-mass dark matter candidates to improve our chances of achieving it. A varied and ongoing portfolio of experiments spanning different scales and detection methods is essential to maximize our chances of discovering its composition. This report paper provides an updated overview of the Brazilian community's activities in dark matter and dark sector physics over the past years with a view for the future. It underscores the ongoing need for financial support for Brazilian groups actively engaged in experimental research to sustain the Brazilian involvement in the global search for dark matter particles
未来十年的关键科学目标之一是揭示暗物质(DM)的本质。我们应该继续优先考虑弱相互作用大质量粒子(WIMPs)、轴子和其他低质量暗物质候选体等目标,以提高我们实现这一目标的机会。为了最大限度地提高我们发现暗物质组成的机会,我们必须持续进行各种不同规模和探测方法的实验组合。本报告文件概述了巴西暗物质和暗部门物理学界过去几年的最新活动,并展望了未来。它强调了对积极从事实验研究的巴西团体提供财政支持的持续需求,以保持巴西对暗物质粒子全球搜索的参与。
38. Exotics in the $πD$ systemid:2111.15544:id在线阅读
Eric B. Gregory, Feng-Kun Guo, Christoph Hanhart, Stefan Krieg, Thomas Luu
In this proceedings we consider several states, namely the $D^*_{s0}(2317)$, $D_{s1}(2460)$, $D^*_{0}(2300)$ and $D_{1}(2430)$, which appear to defy description as simple quark-antiquark pairs. Theoretical input from unitarized chiral perturbation theory suggests they can be understood as emerging from Goldstone-Boson--$D$-meson scattering. We present results from an $SU(3)$ flavor-symmetric lattice QCD simulation at large pion masses suggesting that there exists a $\pi D$ bound state in the flavor-sextet representation that cannot emerge for quark-antiquark states, but that appears naturally from the multiquark states. Moreover, we find repulsion in the [15] representation, which establishes the pattern predicted for the interactions of Goldstone bosons with $D$ mesons. This suggests these states may have the structure of hadronic molecules.
在这篇论文中,我们考虑了几种状态,即$D^*_{s0}(2317)$、$D_{s1}(2460)$、$D^*_{0}(2300)$和$D_{1}(2430)$,它们似乎无法被描述为简单的夸克-反夸克对。来自单元化手性扰动理论的理论输入表明,它们可以被理解为来自金石-玻色子-$D$介子散射。我们展示了在大先锋质量下的$SU(3)$味道对称晶格QCD模拟结果,表明在味道-六元表示中存在一个$\pi D$束缚态,它不能出现在夸克-反夸克态中,而是从多夸克态中自然出现的。此外,我们在[15]表示中发现了斥力,这建立了金石玻色子与$D$介子相互作用的预言模式。这表明这些态可能具有强子分子的结构。
39. Reconciling cosmic dipolar tensions with a gigaparsec voidid:2211.06857:id在线阅读
Tingqi Cai, Qianhang Ding, Yi Wang
Recent observations indicate a $4.9\sigma$ tension between the CMB and quasar dipoles. This tension challenges the cosmological principle. We propose that if we live in a gigaparsec scale void, the CMB and quasar dipolar tension can be reconciled. This is because we are unlikely to live at the center of the void. And a within 10\% offset from the center will impact the quasars and CMB differently in their dipolar anisotropies. As we consider a large and thick void, our setup can also ease the Hubble tension.
最近的观测表明,CMB 和类星体偶极子之间存在着 4.9 美元的张力。这种张力对宇宙学原理提出了挑战。我们提出,如果我们生活在千兆秒尺度的虚空中,CMB 和类星体偶极张力是可以调和的。这是因为我们不太可能生活在虚空的中心。而与中心10%以内的偏移会对类星体和CMB的偶极各向异性产生不同的影响。由于我们考虑的是一个又大又厚的虚空,我们的设置也可以缓解哈勃张力。
40. Old Data, New Forensics: The First Second of SN 1987A Neutrino Emissionid:2306.08024:id在线阅读
Shirley Weishi Li, John F. Beacom, Luke F. Roberts, Francesco Capozzi
The next Milky Way supernova will be an epochal event in multi-messenger astronomy, critical to tests of supernovae, neutrinos, and new physics. Realizing this potential depends on having realistic simulations of core collapse. We investigate the neutrino predictions of nearly all modern models (1-, 2-, and 3-d) over the first $\simeq$1 s, making the first detailed comparisons of these models to each other and to the SN 1987A neutrino data. Even with different methods and inputs, the models generally agree with each other. However, even considering the low neutrino counts, the models generally disagree with data. What can cause this? We show that neither neutrino oscillations nor different progenitor masses appear to be a sufficient solution. We outline urgently needed work.
下一颗银河系超新星将是多信使天文学的一个划时代事件,对于检验超新星、中微子和新物理学至关重要。要实现这一潜力,就必须对内核坍缩进行逼真的模拟。我们研究了几乎所有现代模型(1维、2维和3维)对最初$\simeq$1 s的中微子预测,首次详细比较了这些模型之间以及它们与SN 1987A中微子数据之间的差异。即使采用了不同的方法和输入,这些模型总体上是一致的。然而,即使考虑到低中微子计数,模型与数据也普遍不一致。这是什么原因造成的呢?我们的研究表明,中微子振荡和不同的原生质量似乎都不足以解决问题。我们概述了急需开展的工作。
41. The irreversible relaxation of inflationid:2307.04803:id在线阅读
Robert Alicki, Gabriela Barenboim, Alejandro Jenkins
Based on the results of a previous analysis of the Markovian master equation for the irreversible evolution of an open system embedded in de Sitter space, we include in the cosmological Friedmann equations a contribution from the presence of a physical bath at temperature $T_{\rm dS} = h / 2 \pi$, where $h$ is the Hubble parameter. We show that this provides a mechanism for the irreversible relaxation of the cosmological constant and a graceful exit to inflation, without need for subsequent reheating. Thermal particle production during inflation gives adiabatic, Gaussian, and approximately scale-invariant cosmological perturbations. We thus obtain the main features of inflation without any inflaton potential. To clarify the thermodynamic interpretation of these results, we consider the analogy of this irreversible relaxation to superfluorescence in quantum optics.
基于之前对嵌入德西特空间的开放系统不可逆演化的马尔可夫主方程的分析结果,我们在宇宙学弗里德曼方程中加入了温度为$T_{\rm dS} = h / 2 \pi$的物理浴的贡献,其中$h$是哈勃参数。我们的研究表明,这为宇宙常数的不可逆松弛提供了一种机制,并且可以优雅地退出暴胀,而不需要随后的再加热。在暴胀过程中产生的热粒子给出了绝热、高斯和近似尺度不变的宇宙学扰动。因此,我们在没有任何膨胀势的情况下获得了暴胀的主要特征。为了澄清这些结果的热力学解释,我们将这种不可逆弛豫类比为量子光学中的超荧光。
42. Extracting more information from entropyid:2501.02668:id在线阅读
L. Araque, W. Barreto
We extract the complex frequency of the lowest quasi-normal mode from the holographically computed entropy density near thermodynamic equilibrium. The system consists of a purely thermal Supersymmetric Yang-Mills N=4 plasma in homogeneous isotropization dynamics. The initial state is far-from-equilibrium, proceeding to thermalization over time. The system evolves to equilibrium entropy forming a stairway pattern. The analysis reveals that the rate of increase of the stairway is twice the decay rate of the lowest quasi-normal mode. This leads us to propose a model explaining how this information is encoded in entropy. The model is extended to consider finite temperature, R-charge density and scalar condensate of the medium, disclosing an additional feature. The system's main dissipation channel may shift to one driven by the scalar condensate, depending on the chemical potential.
我们从热力学平衡附近的全息计算熵密度中提取了最低准正常模式的复频率。该系统由处于同质等向动力学中的纯热超对称杨-米尔斯 N=4 等离子体组成。初始状态远离平衡,随着时间的推移逐渐热化。系统演化到平衡熵形成了一个阶梯模式。分析表明,阶梯上升率是最低准正常模式衰减率的两倍。由此,我们提出了一个模型,解释熵如何编码这一信息。该模型被扩展到考虑有限温度、R-电荷密度和介质的标量凝结物,从而揭示了一个额外的特征。根据化学势的不同,系统的主要耗散通道可能会转变为由标量冷凝物驱动的通道。
43. Understanding thermalization in a non-Abelian gauge theory in terms of its soft modesid:2501.04397:id在线阅读
Sayak Guin, Harshit Pandey, Sayantan Sharma
We measure the maximal Lyapunov exponent $\lambda_L$ of physical states in a SU(2) gauge theory consisting of soft momentum modes both in and out-of-thermal equilibrium conditions using ab-initio lattice techniques. We have implemented different algorithms to appropriately describe the dynamics of soft-modes for a wide range of temperatures and under non-equilibrium conditions. The non-equilibrium state has been realized starting from an over-occupied initial condition for low momentum soft gluons whereas the thermal state comprises of strongly interacting soft gluons at temperatures where these are well separated from the hard momentum modes. Spectra of positive Lyapunov exponents is observed in both these states, similar to a chaotic dynamical system. From the Kolmogorov-Sinai entropy rate measured in terms of this spectrum, we estimate a typical time-scale of $\sim 0.50(3)$ fm/c to achieve thermalization at $T\sim 600$ MeV starting from the non-thermal state. We also measure, for the first time, the $\lambda_L$ for long wavelength critical modes of SU(2) using the out-of-time-ordered correlator of a classical $Z_2$ scalar field theory, which shares the same universal behavior with SU(2), near the deconfinement phase transition. The $\lambda_L$ is observed to maximize at the transition temperature.
我们利用非原位晶格技术测量了由软动量模组成的 SU(2) 轨则理论中物理状态在热平衡条件下和非热平衡条件下的最大 Lyapunov 指数 $\lambda_L$。我们采用了不同的算法,以恰当地描述各种温度范围和非平衡条件下软动量模式的动力学。非平衡态是从低动量软胶子的过占初始条件开始实现的,而热态则包括在温度下强相互作用的软胶子,这些软胶子与硬动量模式有很好的分离。在这两种状态下都能观察到正李亚普诺夫指数谱,类似于混沌动力学系统。根据该频谱测得的柯尔莫哥洛夫-西奈熵率,我们估算出在 $T\sim 600$ MeV 下从非热态开始实现热化的典型时间尺度为 $\sim 0.50(3)$ fm/c。我们还首次使用经典 $Z_2$ 标量场理论的时序外相关器测量了 SU(2) 长波临界模的 $\lambda_L$,该理论与 SU(2) 具有相同的普遍行为,即在去抵消相变附近。观察到 $\lambda_L$ 在转变温度下达到最大值。
44. Analysis of symmetries in the Causal Loop-Tree Duality representationsid:2502.14179:id在线阅读
Irene Lopez Imaz, German Sborlini
Unveiling hidden symmetries within Feynman diagrams is crucial for achieving more efficient computations in high-energy physics. In this paper, we study the symmetries underlying the causal Loop-Tree Duality (LTD) representations through a {graph-theoretic} analysis. Focusing on the integrand-level representations of $N$-point functions at one loop, we examine their degeneration and discover that different causal representations are interconnected through specific transformations arising from the symmetries of cut diagrams. Furthermore, the degeneration is linked to algebraic constraints among the different causal thresholds. Our findings shed new light on the deeper structures of Feynman integrals and pave the way for significantly accelerating their calculation by interrelating different approaches.
揭示费曼图中隐藏的对称性对于实现更高效的高能物理计算至关重要。在本文中,我们通过{图论}分析研究了因果环-树对偶性(LTD)表征背后的对称性。我们以一个环上 $N$ 点函数的积分级表示为重点,研究了它们的退化,发现不同的因果表示通过由切割图对称性产生的特定变换而相互关联。此外,退化还与不同因果阈值之间的代数约束有关。我们的发现为费曼积分的深层结构提供了新的启示,并为通过不同方法之间的相互联系来大大加快其计算速度铺平了道路。
45. Magnetar structure in non-linear electrodynamics with mixed poloidal-toroidal fieldsid:2503.01409:id在线阅读
Arthur G. Suvorov, José A. Pons
Magnetars have inferred polar field strengths in excess of the Schwinger limit, where non-linear electromagnetic effects can be significant. Their internal fields may be even stronger, suggesting that Maxwellian characterizations of hydromagnetic structure may require revision. A generalized Grad-Shafranov equation, describing static and axisymmetric fluid stars with mixed poloidal-toroidal fields, is introduced and subsequently solved in a perturbative scheme to calculate quadrupolar deformations. In the Born-Infeld theory, we show that the toroidal field has a maximum strength set by the scale parameter, $b$, implying an upper limit to the stellar prolateness, $|\epsilon_{\rm max}| \sim 10^{-5} \left(b/10^{16}\text{ G}\right)^2$, that is independent of field specifics. Observations of magnetar phenomena that are interpreted as evidence for ellipticity, such as precession, can thus implicitly constrain post-Maxwellian parameters in a way that complements terrestrial experiments. Toroidal ceilings also have implications for dynamo theory and gravitational waves, which we revisit together with field evolution in crusts abiding by beyond-Maxwell physics.
磁星的推断极场强度超过了施温格极限,非线性电磁效应在这里可能非常明显。它们的内部磁场可能会更强,这表明可能需要对水磁结构的麦克斯韦特征进行修正。本文引入了一个广义的格拉德-沙弗诺夫方程(Grad-Shafranov equation),该方程描述了具有极环形-环形混合场的静态和轴对称流体星体,随后通过扰动方案求解了四极变形的计算。在玻恩-因费尔德理论中,我们证明了环状场有一个由尺度参数$b$设定的最大强度,这意味着恒星增殖性的上限为$|\epsilon_{\rm max}| \sim 10^{-5}.\left(b/10^{16}text/{G}/right)^2$,这与磁场的具体情况无关。因此,对被解释为椭圆性证据的磁星现象(例如前冲)的观测,可以以一种补充陆地实验的方式隐含地约束后麦克斯韦参数。环状顶点还对动力理论和引力波有影响,我们将结合遵守超越麦克斯韦物理学的地壳中的场演化来重新讨论这一点。