The Damping of energetic gluons and quarks in high temperature QCD

Jul, 1991
9 pages
Published in:
  • Phys.Rev.D 45 (1992) 17-20
e-Print:
Report number:
  • MCGILL-91-24

Citations per year

19922000200820162024024681012
Abstract: (arXiv)
When a gluon or a quark is sent through the hot QCD plasma it can be absorbed into the ambient heat bath and so can acquire an effective lifetime. At high temperatures and for weak couplings the inverse lifetime, or damping rate, for energetic quarks and transverse gluons, (those whose momenta satisfy |\p| \gg gT) is given by \gamma(\p) = c\/ g^2 \log\left({1\over g}\right)\/ T + O(g^2T). We show that very simple arguments suffice both to fix the numerical coefficient, cc, in this expression and to show that the O(g2T)O(g^2T) contribution is incalculable in perturbation theory without further assumptions. For QCD with NcN_c colours we find (expressed in terms of the casimir invariants Ca=NcC_a=N_c and Cf=(Nc21)/(2Nc)C_f=(N_c^2-1)/(2N_c)): cg=+Ca4πc_g=+{C_a\over 4\pi} for gluons and cq=+Cf4πc_q=+{C_f\over 4\pi} for quarks. These numbers agree with the more detailed calculations of Pisarski \etal\ but disagree with those of Lebedev and Smilga. The simplicity of the calculation also permits a direct verification of the gauge-invariance and physical sign of the result.
  • talk
  • quantum chromodynamics: perturbation theory
  • quark gluon: plasma
  • energy loss
  • finite temperature
  • infrared problem
  • plasma: oscillation
  • gluon: propagator
  • gluon: transverse