2025/05/15 by Ardit Krasniqi, Krasniqi, Ardit, Marco Cè +7
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Lattice (hep-lat) #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions
paper · pdf · doi:10.48550/arxiv.2505.10295
openalex publication_date 2025/05/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
Determining the spectrum of photons emitted by the quark-gluon plasma non-perturbatively remains an open computational challenge. In this letter we calculate two moments of that spectrum at a temperature T≈ 254 MeV, employing lattice QCD with two flavors of O(a)-improved Wilson fermions, without facing an inverse problem. Our central value for the difference of these two moments, which is sensitive to photon energies ω\gtrsim πT, is lower than, but compatible with that obtained by integrating the leading-order weak-coupling photon spectrum. This study informs the direct photon puzzle in heavy-ion collision phenomenology, where it has proved difficult to simultaneously explain the yield and azimuthal anisotropy of photons not originating from final-state hadronic decays.