标题： 核子和$Δ$介子在强磁场中的行为 显示英文标题

标题： Nucleon and $Δ$ isobar in a strong magnetic field

摘要： 我们研究了在强磁场存在下核子的静态性质，并基于Skyrme模型讨论了核子结构的相应变化。 结果表明，在大磁场值（$\sim10^{17}$到$10^{18} \mathrm{G}$）下，这可能出现在RHIC能量下的重离子碰撞实验中，孤立子开始偏离球对称形式，其尺寸也开始变化。 在极端大的磁场值（$\sim 10^{19}$G）下，这可能在LHC实验中发现，孤立子比在自由空间中更加紧凑。 结果还表明，在外部磁场存在下，核子的质量通常趋于增加，而来自同位旋对称性的$\Delta$同位素的质晕简并将被解除。 我们还讨论了由于外部磁场的影响，$\Delta$与核子$\Delta m_{\Delta\mathrm{N}}$之间的质量差的变化。 我们发现，$\Delta m_{\Delta\mathrm{N}}$随着磁场强度的增加而增加。 显示英文摘要

摘要： We investigate the static properties of the nucleon in the presence of strong magnetic fields and discuss the consequent changes of the nucleon structure, based on the Skyrme model. The results show that at large values of the magnetic field ($\sim10^{17}$ to $10^{18} \mathrm{G}$), which is supposed to appear in heavy-ion collision experiments at RHIC energies, the soliton starts to deviate from the spherically symmetric form and its size starts to change. At extremely large values of the magnetic field ($\sim 10^{19}$ G), which may be found at the LHC experiments, the soliton becomes more compact than in free space. The results also show that in the presence of the external magnetic field, the mass of the nucleon tends to increase in general and the mass degeneracy of the $\Delta$ isobars from isospin symmetry will be lifted. We also discuss the changes in the mass difference between the $\Delta$ and the nucleon, $\Delta m_{\Delta\mathrm{N}}$, due to the influence of the external magnetic field. We find that $\Delta m_{\Delta\mathrm{N}}$ increases as the strength of the magnetic field grows.