This paper presents a systematic study of hyperon non-leptonic two-body decays induced by light quark transitions, particularly the $ s \rightarrow u\bar{u}d $ process, within the framework of $\textit{SU}$(3) flavor symmetry. The effective weak Hamiltonian is decomposed into irreducible $\textit{SU}$(3) representations, including the 27-plet and octet components, and applied to analyze decays of octet and decuplet baryons and charmed baryons. Both the irreducible representation amplitude (IRA) approach and the topological diagrammatic analysis (TDA) are employed to construct decay amplitudes and constrain the parameter space. $\textit{SU}$(3) symmetry-breaking effects arising from the strange quark mass are incorporated systematically. A global fit to current experimental data allows us to extract form factors and predict branching ratios and asymmetry parameters for several decay channels. Our results demonstrate the predictive power of $\textit{SU}$(3) flavor symmetry while highlighting significant symmetry-breaking effects, especially in amplitudes related to the 27-plet. Notably, the $ \Sigma^+ \rightarrow p\pi^0 $ decay channel exhibits a deviation exceeding $ 1\sigma $ from experimental measurements, suggesting the possible presence of new decay mechanisms or contributions beyond the Standard Model. Besides, we also evaluate the size of symmetry breaking. However, the large uncertainty of the experimental data makes it difficult to precisely determine the value of symmetry breaking. We strongly recommend that future experimental efforts aim to reduce the measurement uncertainties, especially for the processes $ \Lambda^0\to p\pi^- $ and $ \Lambda^0\to n\pi^0 $ , which have larger experimental errors compared to other data and play an important role in determining the symmetry breaking parameter. This study provides a systematic framework for future tests of the Standard Model and the search for new physics in hyperon decays.

China

Xin Wu

Qi Chen

Ye Xing

Zhi-Peng Xing

Ruilin Zhu

$\textit{SU}$(3) flavor symmetry analysis of hyperon non-leptonic two body decays * Ruilin Zhu is supported by NSFC (12322503, 12075124) and the Natural Science Foundation of Jiangsu (BK20211267). Zhi-Peng Xing is supported by NSFC (12375088, 12335003, 12405113). Ye Xing is supported by NSFC (12005294)

Dark matter (DM) annihilation can be significantly enhanced through narrow resonances or the Sommerfeld enhancement effect, with both mechanisms potentially combining in a super-resonant annihilation process. In such scenarios, the conventional assumption that kinetic equilibrium persists until chemical decoupling may not hold, leading to substantial impacts on the final DM relic density. However, a strongly enhanced annihilation cross section into Standard Model particles, except neutrinos, is constrained by cosmic microwave background observations. We thus investigate DM annihilation into neutrino pair final states, focusing on the role of kinetic decoupling. We solve the coupled Boltzmann equations to determine the relic density and constrain the parameter space using current experimental data, while also forecasting the sensitivity of future experiments.

Murat Abdughani

Shao-Song Tang

Kadirya Tursun

Bin Zhu

Neutrinophilic super-resonant dark matter

Self-interacting dark matter (SIDM) can address the small-scale anomalies and previous researches focused on such a SIDM heavier than GeV, for which the self-scattering cross-section is in the quantum resonance region and has a non-trivial velocity dependence. For a SIDM lighter than GeV, the self-scattering cross-section falls within the Born region. In this work, considering the constraints from CMB, BBN and the DM relic density, we investigate the direct detection of the Higgs portal for a sub-GeV SIDM with a scalar mediator. For this end, we consider two approaches: one is the cosmic-ray accelerated dark matter (CRDM) scattering off the nucleon, the other is the electron recoil caused by the halo dark matter. We present direct detection limits for the parameter space of light SIDM and scalar mediator. We find that the detectability in either approach needs a sizable mediator-Higgs mixing angle ( $$\sin \theta $$ ) which is larger than one for the CRDM approach and larger than $$10^{-1}$$ for the electron recoil approach. While the former case cannot be realized in the Higgs-portal light SIDM model with a scalar mediator, the latter case may also be constrained by some astrophysical observations or beam dump experiment. Anyway, even if other constraints are quite stringent, the direct detection may provide independent limits for such a sub-GeV SIDM.

Wu-Long Xu

Jin Yang

Direct detection of Higgs portal for light self-interacting dark matter

We study Carrollian amplitudes of massless scalars in (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>1</mn><mo>+</mo><mn>2</mn></mrow></math>) Minkowski space. Using the prescription recently shown by Alday et al. [Carrollian amplitudes from holographic correlators, <a href="http://dx.doi.org/10.1007/JHEP03(2025)158">J. High Energy Phys. 03 (2025) 158</a>] originally designed for the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>AdS</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math> Witten diagrams, we show that <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>AdS</mi></mrow><mrow><mn>3</mn></mrow></msub></mrow></math> Witten diagrams in position space in the flat space limit reduce to Carrollian amplitudes. The flat space limit in the bulk is implemented by the Carrollian limit at the boundary. Focusing on four-point correlators with contact and exchange diagrams, we show that the Carrollian limit makes the universality of the bulk point singularity manifest upon performing analytic continuation to the Lorentzian signature of the boundary correlators. Unlike four-point Carrollian amplitudes in (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>1</mn><mo>+</mo><mn>3</mn></mrow></math>) dimensions, the (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>1</mn><mo>+</mo><mn>2</mn></mrow></math>) dimensional ones are nondistributional, having analytic properties simpler than the AdS correlators. We also observe for the first time a double copy structure of Carrollian amplitudes.

United Kingdom

Iustin Surubaru

Carrollian amplitudes and holographic correlators in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>AdS</mi></mrow><mrow><mn>3</mn></mrow></msub><mo>/</mo><msub><mrow><mi>CFT</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></math>

We explore the supernova neutrino-boosted dark matter (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>SN</mi><mi>ν</mi><mi>BDM</mi></mrow></math>) and its direct detection. During core-collapse supernova, an abundance of neutrinos are emitted. These supernova neutrinos can transfer their kinetic energy to the light dark matter via their interactions, and thus are detected in the neutrino and dark matter experiments. Because of the exponential suppression of the high-energy neutrino flux, the kinetic energy carried by a large portion of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>SN</mi><mi>ν</mi><mi>BDM</mi></mrow></math> falls within the MeV range. We consider a simplified model where dark matter interacts with both electrons and neutrinos through a light mediator. In this case, the enhancement in the scattering rate from the light mediator combined with the excitation of the plasmon resonance in silicon significantly enhances the sensitivity in experiments using low-threshold detectors, such as skipper CCDs, in contrast to conventional neutrino and dark matter direct-detection experiments. We calculate the total scattering rate induced by <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>SN</mi><mi>ν</mi><mi>BDM</mi></mrow></math> and derive exclusion limits from Super-K, XENON1T, SENSEI, and DAMIC-M.

Jun-Wei Sun

Lei Wu

Yan-Hao Xu

Probing supernova neutrino boosted dark matter with collective excitations

We develop a formalism for computing the scattering amplitudes in maximally symmetric de Sitter spacetime with compact spatial dimensions. We describe quantum states by using the representation theory of de Sitter symmetry group and link the Hilbert space to “inertial” geodesic observers. The positive and negative “energy” wavefunctions are uniquely determined by the requirement that in observer's neighborhood, short wavelengths propagate as plane waves with positive and negative frequencies, respectively; they define a unique “Euclidean” (a.k.a. Bunch-Davies) de Sitter invariant vacuum, common to all inertial observers. By following the same steps as in Minkowski spacetime, we show that the scattering amplitudes are given by a generalized Dyson's formula. Compared to the flat case, they describe the scattering of wavepackets with the frequency spectrum determined by geometry. The frequency spread shrinks as the masses and/or momenta become larger than the curvature scale. Asymptotically, de Sitter amplitudes agree with the amplitudes evaluated in Minkowski spacetime.

United States

Poland

Tomasz R. Taylor

Scattering of quantum particles in global de Sitter spacetime I: The formalism

Four-point gluon and graviton correlators in celestial holography are famously non-analytic, having distributional support. In this work, we propose an alternative graviton correlator that is analytic and displays several desirable properties. We compute the four-point correlator involving one graviton shadow operator and three graviton primary operators from the celestial four-point graviton amplitudes at tree-level. We perform the conformal block decomposition for the shadow correlator in the compatible channel. For the case when the shadow operator is conformally soft, we compute the single-valued completion of the shadow correlator and perform the conformal block decomposition of the single-valued shadow correlator in all channels. We find an integral representation of the single-valued shadow correlator, which allows us to invert the shadow transform to find the single-valued celestial graviton amplitude. We study various properties of the single-valued celestial graviton amplitude. Interestingly, it exhibits a double copy structure in relation to its counterpart gluon amplitude.

Conformal blocks from celestial graviton amplitudes

In this study, we investigate the $R^2$ corrections to the dissociation of heavy quarkonium in the Gauss-Bonnet gravitational background. We analyze the impact of the Gauss-Bonnet parameter $\lambda_{\rm GB}$ on the spectral function of charmonium and bottomonium and examine the effect of $\lambda_{\rm GB}$ on the dissociation of heavy quarkonium. Our results show that $\lambda_{\rm GB}$ reduces the peak height and increases the peak width of the spectral function, suggesting that $\lambda_{\rm GB}$ enhances the dissociation of heavy quarkonium. We also discuss the variation in the dissociation of heavy quarkonium with the ratio of shear viscosity to entropy density and observe that the dissociation is easier in more perfect plasma. Additionally, we observe that the temperature decreases the peak height and widens the peak, thereby accelerating the dissociation.

Zhou-Run Zhu

Manman Sun

Rui Zhou

Jinzhong Han

$\textit{R}$ $^{2}$ corrections to holographic heavy quarkonium dissociation * Rui Zhou supported by the Science and Technology Development Plan Project of Henan Province, China (242102230085), the National Natural Science Foundation of China (12404470), the High Level Talents Research and Startup Foundation Projects for Doctors of Zhoukou Normal University, China (ZKNUC2023017). Manman Sun supported by the National Natural Science Foundation of China (12305076). Zhou-Run Zhu supported by the High Level Talents Research and Startup Foundation Projects for Doctors of Zhoukou Normal University, China (ZKNUC2023018)

We study the transverse momentum ( $p_T$ ) differential anisotropic flow and flow fluctuation in Pb+Pb collisions at $\sqrt{s_{_{NN}}}$ =5.02 TeV at the LHC. A (3+1)-dimensional CLVisc hydrodynamics framework with fluctuating TRENTO (or AMPT) initial conditions is utilized to simulate the space-time evolution of the quark-gluon plasma (QGP) medium. The effects of shear viscosity and the sub-nucleon structure on anisotropic flow and flow fluctuation are analyzed. Our result shows that shear viscosity tends to suppress both flow coefficients ( ${v_2\{2}\}$ , ${v_2\{4\}}$ , and ${\langle v_2\rangle}$ ) and flow fluctuation ( ${\sigma_{v_2}}$ ) owing to its smearing effect on local density fluctuation. The flow coefficients appear to be insensitive to the sub-nucleon structure, whereas the flow fluctuation ${\sigma_{v_2}}$ tends to be suppressed by the sub-nucleon structure in central collisions but enhanced in peripheral collisions. After taking into account the sub-nucleon structure effect, our numerical result can qualitatively describe the relative flow fluctuations ( ${v_2\{4\}/v_2\{2\}}$ , $F({v_2})$ ) measured by the ALICE Collaboration at the LHC. We further investigate the effects of shear viscosity, sub-nucleon structure, and initial condition model on the flow angle and flow magnitude decorrelations ( ${A_2^f}$ , ${M_2^f}$ ) using the four-particle correlation method. We find that the flow decorrelation effect is typically stronger in central collisions than in peripheral collisions. The flow angle decorrelation is found to be insensitive to the shear viscosity and sub-nucleon structure, whereas the flow magnitude decorrelation shows quite different behaviors when using the TRENTO and AMPT initial condition models. Our study sheds light on the anisotropic flow, transport properties, and initial structure of the QGP created in high-energy nuclear collisions.

Germany

Jie Zhu

Canada

Xiang-Yu Wu

Guang-You Qin

Anisotropic flow, flow fluctuation, and flow decorrelation in relativistic heavy-ion collisions: the roles of sub-nucleon structure and shear viscosity * Supported in part by the Natural Science Foundation of China (12225503, 11890710, 11890711, 11935007). Zhu Jie is supported in part by the China Scholarship Council (202306770009). Wu Xiang-Yu is supported in part by the National Science Foundation within the framework of the JETSCAPE collaboration (OAC-2004571) and in part by the Natural Sciences and Engineering Research Council of Canada. Some of the calculations were performed in the Nuclear Science Computing Center at Central China Normal University (NSC$^{3}$), Wuhan, Hubei, China.

A plasmon, a collective mode of electronic excitation in solid-state detectors, provides a novel way to detect light dark matter (DM). In this work, we present the conditions of DM to produce a plasmon resonance, requiring relativistic velocities for light DM, and generalize the collective excitation framework to account for relativistic DM. As a demonstration, we consider the cosmic ray boosted DM and find that the plasmon resonance can be significantly enhanced in the scenario with a light mediator. Utilizing the first data from the SENSEI experiment with the skipper CCDs at SNOLAB, we obtain a new strong limit on the sub-MeV DM-electron scattering cross section.

Zheng-Liang Liang

Liangliang Su

Plasmon-Enhanced Direct-Detection Method for Boosted Sub-MeV Dark Matter