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Zhi-Bin Wang

Publications and source records attributed to Zhi-Bin Wang.

5 recordsLinked to original sources

Stationary electron vortex states in a plasma bubble field

Plasma wakefield accelerators (PWFAs) offer accelerating gradients of 10-100~GV/m and relativistically propagating plasma bubbles capable of confining charged particles. We study the stationary states of a vortex electron at the bubble center by solving the corresponding quasi-relativistic Schrödinger equation. Analytical solutions are obtained with Laguerre-Gaussian transverse modes and Hermite-Gaussian longitudinal envelopes. Comparing the resulting beam parameters with experimentally accessible vortex-electron bundles, we find that the transverse beam waist supported by the plasma bubble is comparable to that achieved by current electron-optical techniques. The longitudinal confinement further provides a favorable parameter regime for stable injection. Our results indicate the feasibility of maintaining localized vortex-electron states in a plasma-bubble wakefield and provide an analytical starting point for investigating their subsequent acceleration and stability.

physics.acc-ph↗

Robustness of Off-Axis Electron Vortices in Nonuniform Magnetic Fields

Rotational symmetry protects the topological charge of on-axis electron vortices but not of off-axis vortices. We identify an additional SU(1,1) dynamical invariant that guarantees conservation of their intrinsic orbital angular momentum within the near-axis approximation. First-principles simulations of an off-axis electron vortex traversing a Glaser lens confirm this prediction, establishing a robust transport mechanism in axisymmetric nonuniform magnetic fields.

physics.acc-ph↗

Ionization-Induced Electrostatic Hose Instability in Electron-Beam-Sustained Plasmas

We report the discovery of a previously unrecognized electrostatic hose instability in electron-beam-sustained plasmas, driven by the coupling between the electron beam centroid and the plasma generated via the beam-impact ionization. Unlike the conventional hose instability of relativistic beams propagating in underdense plasmas, this instability requires only ionization-capable electron beams readily produced by common emission processes and sheath acceleration, indicating broad relevance across various discharges. A linear theory is developed to predict the hosing frequency and growth rate, and particle-in-cell/Monte Carlo simulations confirm both the onset of instability and the theoretical predictions.

physics.plasm-ph↗

Electromagnetic form-factor of the $π$ meson with light-cone QCD sum rules

In this article, we calculate the electromagnetic form-factor of the $π$ meson with the light-cone QCD sum rules. The numerical value $F_π^{p}(0) =0.999\pm 0.001$ is in excellent agreement with the experimental data (extrapolated to the limit of zero momentum transfer, or the normalization condition $F_π(0)=1$). For large momentum transfers, the values from the two sum rules are all comparable with the experimental data and theoretical estimations.

hep-ph↗

Analysis of the vertex $D^*D^* ρ$ with the light-cone QCD sum rules

In this article, we analyze the vertex $D^*D^*ρ$ with the light-cone QCD sum rules. The strong coupling constant $g_{D^*D^*ρ}$ is an important parameter in evaluating the charmonium absorption cross sections in searching for the quark-gluon plasmas. Our numerical value for the $g_{D^*D^*ρ}$ is consistent with the prediction of the effective SU(4) symmetry and vector meson dominance theory.

hep-ph↗