节点文献
QCD相结构的全息模型研究
QCD phase structure from holographic models
【摘要】 探寻量子色动力学(Quantum Chromodynamics,QCD)相结构一直是高能重离子碰撞物理研究的重要目标。近年来,转动背景下的QCD相变引起了研究者们的关注。本文基于AdS/QCD对偶,研究了化学势、角速度对QCD临界点的影响。研究发现:化学势减小了临界转速ωc,角速度降低了μc和相变温度。我们通过计算一些可以表征QCD相变的探针,如拖曳力、扩散系数、喷注淬火参数和J/ψ的谱函数,发现喷注淬火参数和拖曳力在相变温度附近有增强,峰值所对应的温度随着化学势的增加降低,这与相图中相变温度随化学势增加而降低相对应。谱函数的结果表明,磁场促进重介子的溶解,使末态J/ψ产额的压低更明显。我们研究了早期宇宙QCD全息相变产生的引力波,发现胶子凝聚抑制了引力波的能量密度,峰值频率位置随着胶子凝聚增加而下降。
【Abstract】 We aim to study the effects of chemical potential and angular velocity on the critical endpoint of quantum chromodynamics(QCD). We used several probes(drag force, jet quenching parameter, heavy vector meson spectral function) to characterize the phase transition and studied gravitational waves from the holographic QCD phase transition in the early universe. We used different holographic QCD models to discuss the QCD phase transition, energy loss, spectral function, and gravitational waves. We found that the chemical potential and angular velocity changed the location of the critical endpoint, and the drag force and jet quenching parameter were temperature dependent and enhanced near the phase transition temperature. The magnetic field had a nontrivial effect on the spectral function. We conclude that the chemical potential decreases ωc, and the angular velocity decreases μc and the phase transition temperature. The jet quenching parameter and drag force can characterize the phase transition, and the magnetic field promotes the dissociation of heavy vector mesons. Moreover, the energy density of gravitational waves decreases as the gluon condensate increases, and the peak frequency shifts downward with increasing gluon condensate. Exploring the phase structure of QCD is an important task in high-energy heavy ion collision physics, and recently, there has been considerable interest in the QCD phase transition for rotating backgrounds.
【Key words】 Phase transition; Energy loss; Spectral function; Gravitational waves;
- 【文献出处】 核技术 ,Nuclear Techniques , 编辑部邮箱 ,2023年04期
- 【分类号】O572.243
- 【下载频次】4