标题： 夸克-强子相变的锐度和杂化星的性质 显示英文标题

标题： The sharpness of the quark-hadron transition and the properties of hybrid stars

摘要： 我们研究了介于强子物质和夸克物质之间的相变的尖锐程度对中子星各种性质的影响。 我们通过使用高斯函数将一个强子模型与一个夸克模型结合，构建了混合状态方程。 这种方法引入了一个由两个参数表征的平滑过渡：一个参数表示相对于一阶相变点的过压，另一个参数与混合区域在重子化学势中的扩展范围有关。 我们发现相变的尖锐程度显著影响状态方程，其偏差可达几十个$\text{MeV fm}^{-3}$，与具有尖锐一阶相变的状态方程不同。 声速表现出多种行为，包括急剧下降、显著峰值和振荡模式，这取决于尖锐度参数。 在恒星结构方面，虽然最大中子星质量基本上不受相变尖锐度的影响，但恒星半径可能会显著变化。 更平滑的过渡会导致对应于混合星的质量-半径曲线段向左移动（最多1公里）。 潮汐可变形性随着过渡的平滑而减小，尤其是对于高质星星体。 我们的结果非常普遍，不依赖于所采用的具体强子和夸克物质模型。 事实上，从夸克-强子面团相的微观模型中得出的混合状态方程和恒星特性表现出与上述相同的特性。 显示英文摘要

摘要： We investigate the effects of the sharpness of the phase transition between hadronic matter and quark matter on various properties of neutron stars. We construct hybrid equations of state by combining a hadronic model with a quark model using a Gaussian function. This approach introduces a smooth transition characterized by two parameters: one representing the overpressure relative to the first-order phase transition point, and the other related to the range over which the hybrid region extends in baryon chemical potential. We find that the sharpness of the phase transition significantly influences the equation of state, which can deviate by several tens of $\text{MeV fm}^{-3}$ from the one with a sharp first-order transition. The speed of sound exhibits diverse behaviors, including drastic drops, pronounced peaks, and oscillatory patterns, depending on the sharpness parameters. In terms of stellar structure, while the maximum neutron star mass remains largely unaffected by the sharpness of the phase transition, the stellar radii can vary significantly. Smoother transitions lead to a leftward shift (up to 1 km) of the mass-radius curve segment corresponding to hybrid stars. The tidal deformability decreases with smoother transitions, especially for higher-mass stars. Our results are quite general and do not qualitatively depend on the specific hadronic and quark matter models employed. In fact, the hybrid equation of state and stellar properties derived from microscopic models of quark-hadron pasta phases display the same behavior as described above.