2020/04/30 by Gunnar Bali, Gunnar S. Bali, Gergely Endrődi +1 · 56 citations
Physics and Astronomy · #Angular momentum #Condensed matter physics #Diamagnetism #Extrapolation #High-Energy Particle Collisions Research #Magnetic field #Magnetic susceptibility #Paramagnetism #Physics #Pulsars and Gravitational Waves Research #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #Quantum electrodynamics #Quantum mechanics #hep-lat #hep-ph #nucl-th
paper · pdf · doi:10.1007/jhep07(2020)183
published in Journal of High Energy Physics 2020(7) (Springer Nature) · 41 pages, 12 figures, 1 ancillary python script, v2: one new figure, new reference, minor changes, v3: more figure panels, new references, volume dependence study extended, 1 formula in App C.5 corrected, minor changes
openalex publication_date 2020/07/01 · arxiv created 2020/07/28 · arxiv updated 2020/07/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
A bstract We determine the magnetic susceptibility of thermal QCD matter by means of first principles lattice simulations using staggered quarks with physical masses. A novel method is employed that only requires simulations at zero background field, thereby circumventing problems related to magnetic flux quantization. After a careful continuum limit extrapolation, diamagnetic behavior (negative susceptibility) is found at low temperatures and strong paramagnetism (positive susceptibility) at high temperatures. We revisit the decomposition of the magnetic susceptibility into spin- and orbital angular momentum- related contributions. The spin term — related to the normalization of the photon lightcone distribution amplitude at zero temperature — is calculated non-perturbatively and extrapolated to the continuum limit. Having access to both the full magnetic susceptibility and the spin term, we calculate the orbital angular momentum contribution for the first time. The results reveal the opposite of what might be expected based on a free fermion picture. We provide a simple parametrization of the temperature- and magnetic field-dependence of the QCD equation of state that can be used in phenomenological studies.