Details

Autor(en) / Beteiligte

• Burnier, Y.
• Laine, M.
• Langelage, J.
• Mether, L.

Titel

Colour-electric spectral function at next-to-leading order

Ist Teil von

• The journal of high energy physics, 2010-08, Vol.2010 (8), Article 94

Ort / Verlag

Berlin/Heidelberg: Springer-Verlag

Erscheinungsjahr

2010

Link zum Volltext

Quelle

SpringerLink (Online service)

Beschreibungen/Notizen

• The spectral function related to the correlator of two colour-electric fields along a Polyakov loop determines the momentum diffusion coefficient of a heavy quark near rest with respect to a heat bath. We compute this spectral function at next-to-leading order, , in the weak-coupling expansion. The high-frequency part of our result ( ω ≫ T ), which is shown to be temperature-independent, is accurately determined thanks to asymptotic freedom; the low-frequency part of our result ( ω ≪ T ), in which Hard Thermal Loop resummation is needed in order to cure infrared divergences, agrees with a previously determined expression. Our result may help to calibrate the overall normalization of a lattice-extracted spectral function in a perturbative frequency domain T ≪ ω ≪ 1 /a , paving the way for a non-perturbative estimate of the momentum diffusion coefficient at ω → 0. We also evaluate the colour-electric Euclidean correlator, which could be directly compared with lattice simulations. As an aside we determine the Euclidean correlator in the lattice strong-coupling expansion, showing that through a limiting procedure it can in principle be defined also in the confined phase of pure Yang-Mills theory, even if a practical measurement could be very noisy there.