Inelastic and elastic parton scattering in the strongly interacting quark-gluon plasma

We investigate the role of inelastic processes in the strongly interacting quark-gluon plasma (sQGP) based on the effective dynamical quasiparticle model (DQPM). In the DQPM the nonperturbative properties of the sQGP at finite temperature <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mi>T</a:mi></a:math> and baryon chemical potential <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:msub><b:mrow><b:mo>μ</b:mo></b:mrow><b:mi>B</b:mi></b:msub></b:math> are described in terms of strongly interacting off-shell partons (quarks and gluons) with dynamically generated spectral functions whose properties are adjusted to reproduce the lattice QCD equation of state for the quark-gluon plasma in thermodynamic equilibrium. For the first time the massive gluon radiation processes from the off-shell quark-quark <c:math xmlns:c="http://www.w3.org/1998/Math/MathML"><c:mrow><c:mo>(</c:mo><c:mi>q</c:mi><c:mo>+</c:mo><c:mi>q</c:mi><c:mo>)</c:mo></c:mrow></c:math> and quark-gluon <d:math xmlns:d="http://www.w3.org/1998/Math/MathML"><d:mrow><d:mo>(</d:mo><d:mi>q</d:mi><d:mo>+</d:mo><d:mi>g</d:mi><d:mo>)</d:mo></d:mrow></d:math> scatterings are calculated explicitly within leading-order Feynman diagrams with effective propagators and vertices from the DQPM without any further approximations. We present the results for the energy and temperature dependencies of the total and differential radiative cross sections and compare them to the corresponding elastic cross sections. We show that our results reproduce the perturbative QCD calculations in the limit of zero masses and widths of quasiparticles. Also we study the μ<e:math xmlns:e="http://www.w3.org/1998/Math/MathML"><e:msub><e:mrow/><e:mi>B</e:mi></e:msub></e:math> dependence of the inelastic cross sections. Moreover, we present estimates for the transition rate and relaxation time of radiative versus elastic scatterings in the sQGP. Published by the American Physical Society 2024