Dilepton production from a nonequilibrium quark - gluon plasma in ultrarelativistic nucleus-nucleus collisions

Nov, 1990
61 pages
Published in:
  • Phys.Rev.D 43 (1991) 2871-2891
Report number:
  • MIT-CTP-1913

Citations per year

199119982005201220180246810
Abstract: (APS)
Dilepton production from a nonequilibrium quark-gluon plasma produced in ultrarelativistic nucleus-nucleus collisions is studied, based on the flux-tube model which has been formulated in terms of a model relativistic Boltzmann-Vlasov equation with a boost-invariant particle source term. This model kinetic equation is solved with the collision term in the relaxation-time approximation. In the collisionless limit, the solution of the kinetic equation becomes oscillatory, indicating the spontaneous excitation of the plasma oscillation. We study how such a nonequilibrium evolution of the system is reflected in the dilepton spectrum. It is shown that the dileptons emitted during such a nonequilibrium stage of matter evolution does not necessarily lead to a spectrum which interpolates smoothly the spectrum from thermal emission and that from the Drell-Yan mechanism. Our results show, on the contrary, that the dilepton spectrum is softened significantly in the absence of thermalization. MT scaling, which is expected in scaling one-dimensional hydrodynamic evolution, is also broken due to the anisotropy in the phase-space distribution of quarks.
  • nucleus nucleus: nuclear reaction
  • lepton: pair production
  • pair production: lepton
  • quark gluon: plasma
  • plasma: oscillation
  • flux tube
  • thermodynamics
  • scaling
  • hydrodynamics
  • Boltzmann-Vlasov equation
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