arXiv subjects

Zaihong Yang

Publications and source records attributed to Zaihong Yang.

6 recordsLinked to original sources

arXiv2026

Probing Cosmic Ray Composition and Muon-philic Dark Matter via Muon Tomography

This work presents a novel cosmic-ray scattering experiment employing a Resistive Plate Chambers (RPC) muon tomography system. By introducing the scattering angle between incident and outgoing cosmic-ray tracks as a key observable, this approach enables simultaneous studies of secondary cosmic-ray composition and searching for new physics. During a 63-day campaign, 1.18 million cosmic ray scattering events were recorded and analyzed. By performing combined template fits to the observed angular distribution, particle abundances are measured -- for example, resolving the electron component at $\sim 2\%$ precision. Furthermore, constraints are established on elastic muon dark matter (DM) scattering cross-sections for muon-philic dark matter. At the $95\%$ confidence level, the limit reaches 1.61 $\times$ $10^{-17}$ $\rm{cm}^{2}$ for 1 GeV slow DM, demonstrating sensitivity limit to light muon-coupled slow DM, in scenarios where a strongly interacting dark matter component is captured and thermalized within the Earth, leading to large surface densities.

hep-ex↗

arXiv2026

Establishing the $^{40}$Ca$(p,p α)$ reaction at 392 MeV under quasi-free scattering conditions

The $(p,p α)$ reaction offers a direct means to probe preformed $α$-cluster structures in nuclei under quasi-free scattering conditions. Previous studies around 100 MeV provided valuable insights into $α$ clustering, but quantitative comparison with microscopic cluster wave functions remained limited due to strong distortion effects. At higher energies, the reaction mechanism becomes simpler and the distorted-wave impulse approximation (DWIA) provides a more reliable framework for quantitative analysis. In the present work, the $^{40}$Ca$(p,pα)$ reaction was measured at an incident energy of 392 MeV using the high-resolution Grand Raiden and LAS spectrometers at RCNP. Despite the small cross section in this energy region, the achieved resolution allowed clear separation of the ground and excited states of the residual $^{36}$Ar nucleus, and corresponding momentum distributions were extracted. DWIA calculations using a Woods-Saxon $α+ ^{36}$Ar bound-state wave function yielded an experimental spectroscopic factor of $ S_{\mathrm{FAC}}^{\mathrm{WS}} = 0.51 \pm 0.05 $, consistent with the previous result at 101.5 MeV $(0.52 \pm 0.23 )$. This agreement demonstrates that the reaction mechanism is well described across a wide energy range. The present study establishes the feasibility of high-precision $(p,pα)$ measurements at several hundred MeV and highlights their potential as a quantitative probe of $α$ clustering in medium-mass nuclei, forming the basis for systematic studies in both stable and unstable systems.

nucl-ex↗

arXiv2025

The correlation between the $α$-cluster separation and the neutron S-factor in $^{12}$Be

The reduced width amplitudes (RWA) and the spectroscopic factor (S-factor) of $α$-cluster and valence neutron in $^{12}$Be are calculated by the generator coordinates method (GCM) with the cluster model. By fixing the distance between the $α$-clusters' generated coordinates, we make a theoretical experiment to analyze the relationship between the $α$-clustering separation and the orbital occupation of the valence neutron in $^{12}$Be. The analysis of the results shows that the percentage of the $σ$ orbital occupation in $^{12}$Be is positively related to the clustering separation.

nucl-th↗

arXiv2025

Neutron correlations and clustering in neutron-rich nuclear systems

In this paper, we will briefly review the recent progress on neutron correlations and clustering in neutron-rich nuclei from quasi-free scattering experiments. The quasi-free ($p$, $pn$) reaction was measured for Borromean nuclei $^{11}$Li, $^{14}$Be, and $^{17}$B. A surprisingly small $s$-wave component was found for $^{17}$B, revealing a weak neutron halo in $^{17}$B, and the comparative study of the three nuclei shows the surface localization of dineutron correlation and its universality in Borromean nuclei. The two-neutron emission of $^{16}$Be was also studied, finding strong dineutron correlation in $^{16}$Be(g.s.) but weak correlation in $^{16}$Be($2^+$). Two missing-mass measurements using $^{4}$He($^{8}$He, $^{8}$Be) and $^{8}$He($p$, $pα$) reactions provided evidence for the $^{4}n$ resonance, but the $^{3}n$ resonance was not supported by the recent experiment employing the $t(t,^3$He)$^3n$ charge-exchange reaction. The quasi-free $(p,p α)$ reaction has been extended to unstable nuclei, and the recent experiment unravels the $α$-$2n$-$α$ molecule-like cluster structure of $^{10}$Be(g.s.).

nucl-ex↗

arXiv2023

A novel solution for seepage problems using physics-informed neural networks

A Physics-Informed Neural Network (PINN) provides a distinct advantage by synergizing neural networks' capabilities with the problem's governing physical laws. In this study, we introduce an innovative approach for solving seepage problems by utilizing the PINN, harnessing the capabilities of Deep Neural Networks (DNNs) to approximate hydraulic head distributions in seepage analysis. To effectively train the PINN model, we introduce a comprehensive loss function comprising three components: one for evaluating differential operators, another for assessing boundary conditions, and a third for appraising initial conditions. The validation of the PINN involves solving four benchmark seepage problems. The results unequivocally demonstrate the exceptional accuracy of the PINN in solving seepage problems, surpassing the accuracy of FEM in addressing both steady-state and free-surface seepage problems. Hence, the presented approach highlights the robustness of the PINN and underscores its precision in effectively addressing a spectrum of seepage challenges. This amalgamation enables the derivation of accurate solutions, overcoming limitations inherent in conventional methods such as mesh generation and adaptability to complex geometries.

cs.CE↗

arXiv2019

Compression-mode resonances in the calcium isotopes and implications for the asymmetry term in nuclear incompressibility

Recent data on isoscalar giant monopole resonance (ISGMR) in the calcium isotopes $^{40,44,48}$Ca have suggested that $K_τ$, the asymmetry term in the nuclear incompressibility, has a positive value. A value of $K_τ> 0$ is entirely incompatible with present theoretical frameworks and, if correct, would have far-reaching implications on our understanding of myriad nuclear and astrophysical phenomena. This paper presents results of an independent ISGMR measurement with the $^{40,42,44,48}$Ca($α,α^\prime$) reaction at $E_α= 386$ MeV. These results conclusively discount the possibility of a positive value for $K_τ$, and are consistent with the previously-obtained values for this quantity.

nucl-ex↗