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Investigation of Early Plasma Evolution Induced by Ultrashort Laser Pulses
Published on: July 2, 2012
Measuring quark-gluon-plasma thermalization time with dileptons.
Mauricio Martinez1, Michael Strickland
1Helmholtz Research School, Johann Wolfgang Goethe-Universität Frankfurt, Ruth-Moufang-Strasse 1, D-60438 Frankfurt am Main, Germany.
Physical Review Letters
|March 21, 2008
Summary
High-energy dilepton production reveals quark-gluon plasma
Area of Science:
- High Energy Physics
- Nuclear Physics
- Quantum Chromodynamics
Background:
- Quark-gluon plasma (QGP) is a state of matter formed in high-energy nuclear collisions.
- Understanding QGP evolution, particularly its transition to a hydrodynamic state, is crucial.
- Momentum-space anisotropy in the early QGP is a key characteristic impacting its dynamics.
Purpose of the Study:
- To investigate the sensitivity of dilepton production to early-time QGP properties.
- To establish dilepton yield as a probe for QGP isotropization time.
- To quantify early-time momentum-space anisotropies in the QGP.
Main Methods:
- Development of a phenomenological model for QGP evolution.
- Incorporation of time-dependent hard momentum scale, p(hard)(tau), and anisotropy parameter, xi(tau).
- Calculation of medium dilepton yield within this model, interpolating between free streaming and hydrodynamics.
Main Results:
- Dilepton production is shown to be sensitive to the plasma isotropization time, tau(iso).
- The model successfully interpolates between early-time longitudinal free streaming and late-time ideal hydrodynamics.
- Calculated dilepton yields reflect the influence of momentum-space anisotropy.
Conclusions:
- High-energy dilepton yield serves as a sensitive observable for QGP studies.
- Experimental measurements of dilepton production can determine the onset of QGP hydrodynamic expansion.
- This method allows for the quantification of early-time momentum-space anisotropies in the QGP.
