发表机构
Instituto de Física y Astronomía, Universidad de Valparaíso（瓦尔帕莱索大学物理与天文研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究利用伪谱分析全息QCD模型中准正规模的谱稳定性，发现其随温度升高而失稳，伪谱失稳可作为强子熔化与离解的诊断工具。
AI 中文摘要
我们利用伪谱分析研究了非共形全息QCD模型中准正规模的谱稳定性。我们首先考虑软墙模型，聚焦于标量场和矢量场，然后将分析扩展到解析改进的全息QCD（IHQCD）模型，在该模型中我们研究张量胶球涨落。在两种情况下，运动方程都被表述为线性本征值问题，从而可以通过伪谱量化准正规谱对小扰动的失稳程度。我们发现，准正规模的谱稳定性对温度表现出非平凡的依赖性，这反映了全息QCD模型中固有维度尺度的存在。随着温度升高，准正规频率虚部的幅度增大，表明相应的强子激发的衰减率增加且相干性逐渐丧失。在足够高的温度下，准正规频率近似呈线性依赖于温度，尽管这一区域仅在相关的强子态已经熔化后才达到。我们进一步将伪谱失稳与相应谱函数的行为进行比较。我们的结果表明，伪谱失稳的增长提供了谱稳定性丧失的一种互补表征，并可作为全息QCD中强子离解和熔化的有用诊断工具。
英文摘要
We investigate the spectral stability of quasinormal modes in nonconformal holographic QCD models using pseudospectral analysis. We first consider the soft-wall model, focusing on scalar and vector fields, and then extend the analysis to the analytic Improved Holographic QCD (IHQCD) model, where we study tensor glueball fluctuations. In both cases, the equations of motion are formulated as linear eigenvalue problems, allowing the instability of the quasinormal spectrum to small perturbations to be quantified through the pseudospectrum. We find that the spectral stability of the quasinormal modes exhibits a nontrivial dependence on temperature, reflecting the presence of intrinsic dimensionful scales in holographic QCD models. As the temperature increases, the magnitude of the imaginary part of the quasinormal frequencies grows, signaling an increasing decay rate and the progressive loss of coherence of the corresponding hadronic excitations. At sufficiently high temperatures, the quasinormal frequencies approach an approximately linear dependence on temperature, although this regime is reached only after the associated hadronic states have melted. We further compare the pseudospectral instability with the behavior of the corresponding spectral functions. Our results indicate that the growth of pseudospectral instability provides a complementary characterization of the loss of spectral stability and can serve as a useful diagnostic of hadronic dissociation and melting in holographic QCD.
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