Abstract
It was recently proposed that there is a phase in thermal QCD (IR phase) at temperatures well above the chiral crossover, featuring elements of scale invariance in the infrared (IR). Here, we study the effective spatial dimensions of Dirac low-energy modes in this phase, in the context of pure-glue QCD. Our is based on the scaling of mode support toward thermodynamic limit, and hence is an IR probe. Ordinary extended modes, such as those at high energy, have . We find in the spectral range whose lower edge coincides with , the singularity of spectral density defining the IR phase, and the upper edge with , the previously identified Anderson-like nonanalyticity. Details near are unexpected in that only exact zero modes are , while a thin spectral layer near zero is , followed by an extended layer of modes. With only integer values appearing, may have a topological origin. We find similar structure at , and associate its adjacent thin layer () with Anderson-like criticality. Our analysis reveals the manner in which nonanalyticities at and , originally identified in other quantities, appear in . This dimension structure may be important for understanding the near-perfect fluidity of the quark-gluon medium seen in accelerator experiments. The role of in previously conjectured decoupling of IR component is explained.
- Received 25 March 2021
- Accepted 28 June 2021
- Corrected 3 August 2021
DOI:https://doi.org/10.1103/PhysRevLett.127.052303
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.
Published by the American Physical Society
Physics Subject Headings (PhySH)
Corrections
3 August 2021
Correction: A misprint of a relation sign introduced during the production process in the first inline equation of the second sentence in the fourth paragraph has been fixed.