The 4th Topics of Particle, Astro and Cosmo Frontiers (TOPAC 2026) 第4届粒子物理、天体物理和宇宙学前沿国际学术研讨会

Session

Poster Session

17 Apr 2026, 20:25

63. Probing Dark Matter Spike with Gravitational Waves from Early EMRIs in the Milky Way Center

chen feng (中国科学院大学)

17/04/2026, 20:40

Cold dark matter may form dense structures around supermassive black holes (SMBHs), significantly influencing their local environments. These dense regions are ideal sites for the formation of extreme mass-ratio inspirals (EMRIs), in which stellar-mass compact objects gradually spiral into SMBH, emitting gravitational waves (GWs). Space-based gravitational-wave (GW) observatories, such as LISA...

32. Complex τ Electric Dipole Moment from GeV-Scale New Physics

Xinyu Du (SJTU)

Among the charged leptons, the τ electric dipole moment (dτ) is the least constrained. We show that the Im[dτ] imposes strong constraints on new physics that have yet to be discussed. Motivated in particular by the Super Tau-Charm Facility (STCF), which will provide a uniquely clean environment for precision τ-physics, we study the momentum-transfer dependence of dτ(q2) and compare the...

15. Dark matter trio in classically conformal theories: WIMP, supercooling, and monopole

Cheng-Hao Zhan (Beihang Univ.)

Beyond solving the hierarchy problem, classically conformal (CC) theories naturally accommodate dark matter (DM). In this work, we explore the CC $SU(2)_X$ gauge theory with a triplet dark scalar, uncovering three distinct DM scenarios: WIMP, supercooled DM, and monopole. The production mechanisms are strongly influenced by the CC model's unique first-order phase transition evolution history,...

55. Dispersive Bootstrap in Cosmological Collider Physics

Haoyuan Liu (Tsinghua University)

It is widely believed that during inflation heavy particles (m ~ H up to 10^13 GeV) beyond the Standard Model can be produced and they can leave imprints on large cosmic scales. This mechanism provides a unique window to explore physics at extremely high energy scales—a paradigm known as cosmological collider (CC) physics. The central observables in CC physics are inflation correlators...

69. Explaining the ACT Helium Abundance tension via Large Lepton Asymmetry from Axion Inflation

Di Wu (HIAS)

The generation of helical magnetic fields and associated chiral asymmetry via the chiral anomaly is a generic feature in pseudoscalar inflation models. In this talk, we explore a scenario where the inflaton $\phi$ is coupled to a gauged lepton flavor symmetry $U(1)_{L_\mu - L_\tau}$ through a Chern-Simons term $\frac{\alpha}{4f}\phi F \tilde{F}$.

The homogeneous evolution of the inflaton...

70. Exploring muonphilic dark matter with the Z2-even mediator at muon colliders

Ms Wanyun Chen (Nanjing Normal University)

Poster

36. Flavor dependence of chiral symmetry breaking and the conformal window

Yi-huai Chen (Beijing Institute of Technology)

We investigate the phase structure of Quantum Chromodynamics (QCD) in the vacuum as a function of quark flavor number $N_f$ within the chiral limit. By self-consistently solving the coupled DSEs for the quark and gluon propagators in a minimal QCD scheme, we elucidate the nonperturbative dynamics governing dynamical chiral symmetry breaking. Our calculations determin a critical flavor number...

38. Full positivity bounds for anomalous quartic gauge couplings in SMEFT

Fu-Ming Chang (University of Science and Technology of China)

Electroweak boson scattering at the LHC provides a crucial avenue for probing physics beyond the Standard Model, particularly regarding deviations in quartic gauge couplings. We derive the complete set of positivity bounds for the $22$ dimension-$8$ anomalous quartic gauge coupling (aQGC) coefficients within the Standard Model Effective Field Theory (SMEFT). Moving beyond previous studies...

48. Muon-Induced Background Mitigation in the RELICS Experiment

Dr Jijun Yang (西湖大学)

Poster Abstruct
Precise measurement of Coherent elastic neutrino-nucleus scattering (CEvNS) is crucial for constraining the Standard Model and probing neutrino non-standard interactions. The Liquid Xenon Time Projection Chamber (LXeTPC) achieves enhanced signal amplification and lower energy thresholds, making it an ideal technology for CEvNS detection. The RELICS experiment in Taizhou,...

46. Non-Projective Bounds in Gravity and Negativity

Yongjun Xu (HIAS)

We develop a primal bootstrap framework for gravitational effective field theo-
ries based on fully crossing-symmetric dispersion relations, using finite-resolution sampling
instead of smearing. This approach has several key advantages: it allows direct control
over the number of subtractions, makes it possible to impose linearized unitarity beyond
positivity, and gives direct access to...

34. Poster：Improving the detection sensitivity to primordial stochastic gravitational waves with reduced astrophysical foregrounds: Subthreshold binary neutron stars

MIngzheng Li (Shanghai Jiao Tong University)

Stochastic gravitational waves (GWs) consist of a primordial component from early Universe processes and an astrophysical component from compact binary mergers. To detect the primordial stochastic GW background (SGWB), the astrophysical foregrounds must be reduced to high precision, which is achievable for third-generation (3G) ground based GW detectors. Previous studies have shown that the...

14. Probe exotic energy injection from dark sectors through cosmic reionization

孜文 尹 (上海交通大学物理与天文学院（李政道研究所）)

Axions and primordial black holes (PBHs) are well-motivated dark matter candidates that can inject energy into the intergalactic medium (IGM) via decay or evaporation over cosmic history, leaving imprints on the cosmic microwave background (CMB). In recent work, we have derived a model-independent ionization history after recombination from CMB power spectra using a Gaussian process approach,...

19. Probing Dark Matter annihilation in the Galactic Centre with TRIDENT

Xin-Hui Chu (TDLI, SJTU)

We determine the future sensitivity of the TRIDENT neutrino telescope to dark matter annihilation in the Galactic Centre. By applying the full detector design we show that TRIDENT will probe annihilation rates down to $\langle\sigma v\rangle\approx5\times10^{-27}\,{\rm cm}^3\,{\rm s}^{-1}$ for a $10\,{\rm TeV}$ dark matter, which is below the thermal freeze-out benchmark. The analysis is...

21. SN1987A constraints on Hadronically Interacting Sub-GeV Dark Matter

尊 王 (东南大学)

We clarify the plasma effects on the couplings of dark photon and $U(1)_{B-L}$ gauge boson in medium and calculate the production rate of these two models in SN1987A via nucleon bremsstrahlung in detail, along with some secondary production channels. From the stellar cooling argument, we obtain the constraints on dark photon and $U(1)_{B-L}$ gauge boson. A new excluded region arises from the...

64. ULDM-Induced Variations of Fundamental Constants in Space-Based Laser Interferometers

Tingyuan Jiang (ICTP-AP, UCAS)

Ultralight dark matter (ULDM) coupled to the Standard Model can induce coherent oscillations of effective fundamental constants and thereby generate narrow-band signals in precision interferometric experiments. In this work, we investigate how such oscillations imprint signatures on space-based laser interferometers such as LISA and Taiji. Starting from the one-way inter-spacecraft link...

137. Z3对称下的跷跷板门户与超重暗物质

彩霞 杨 (济南大学)

为了解开暗物质之谜以及中微子质量和问题，研究对跷跷板模型进行了一个简单扩展，在跷跷板机制中引入右手中微子，将暗区与中微子物理联系起来，不仅能够解释观测到的微小中微子质量问题，还能通过轻子生成过程解释宇宙的重子不对称性，构建“跷跷板通道”的暗物质模型。然而，在离散的$Z_2$对称模型中，当暗标量$\phi$粒子的质量小于右手中微子N时，即质量排序为 $m_N>m_\phi$...

44. ∆(96)⋊H_CP与 tri-direct CP 方法：中微子混合与质量的预言

丽娜 闫 (西北大学)

基于∆(96)⋊H_CP 对称和 tri-direct CP 方法，系统分析最小跷跷板模型的对称破缺模式。
精准预测中微子混合角、CP 破缺相位及质量谱，为下一代中微子实验提供理论参考。

138. 不同模型下 Z’ 通道暗物质的相关唯象学研究

振伟 王 (济南大学)

暗物质是当今宇宙学与粒子物理学领域的核心未解难题，其粒子本质探索是理论物理研究的前沿热点。标准模型虽然是个比较完美的模型，但它不包含引力相互作用，无法解释暗物质本质是什么。所以，在标准模型的扩展规范对称性框架下，聚焦于“矢量玻色子 Z' 通道”的暗物质产生与探测机制，围绕 U(1)(L_μ-Lτ ) 和 U(1)(B-L) 两类典型模型，系统研究了暗物质的遗迹密度、产生机制、唯象学约束及实验探测前景等。论文旨在阐明 Z'通道暗物质在不同规范扩展下的物理特性，并为未来暗物质探测提供理论支撑。在U(1)(L_μ-Lτ ) 模型中，引入狄拉克费米子 χ 作为暗物质候选者，分析轻暗物质（MeV-GeV尺度）与重暗物质（TeV尺度）下参数空间约束以及Z' 玻色子实验探测范围；在U(1)(B-L)模型中，引入双狄拉克暗费米子 χ1 与 χ2 ...

45. 有限模群Δ(96)对称性下的中微子Littlest Modular Seesaw模型及其对轻子混合与中微子质量的新预言

海志 郝 (西北大学)

基于模对称，我们系统分析了在双右手中微子Littlest Modular Seesaw机制中，模量场τ稳定在模对称固定点处的对称破缺模式。考虑有限模群Δ(96)，我们求出了所有最低与次低权重的三维矢量值模形式，全面扫描了模形式在固定点处的可能排列，筛选出符合最新中微子振荡整体拟合的可行模型。此类模型的轻中微子质量矩阵仅依赖于三个实参数，且最轻中微子质量为零，预言性极强。我们给出了由模对称性固定的新的混合矩阵第一列结构。结合 JUNO 首批结果以及 T2HK、DUNE 的未来探测精度，讨论了这些模最小跷跷板模型的现象学意义。