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arXiv · 1604.08942

Early Time Dynamics of Gluon Fields in High Energy Nuclear Collisions

Joseph I. Kapusta·Guangyao Chen·Rainer J. Fries·Yang Li
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Abstract

Nuclei colliding at very high energy create a strong, quasi-classical gluon field during the initial phase of their interaction. We present an analytic calculation of the initial space-time evolution of this field in the limit of very high energies using a formal recursive solution of the Yang-Mills equations. We provide analytic expressions for the initial chromo-electric and chromo-magnetic fields and for their energy-momentum tensor. In particular, we discuss event-averaged results for energy density and energy flow as well as for longitudinal and transverse pressure of this system. Our results are generally applicable if $τ< 1/Q_s$. The transverse energy flow of the gluon field exhibits hydrodynamic-like contributions that follow transverse gradients of the energy density. In addition, a rapidity-odd energy flow also emerges from the non-abelian analog of Gauss' Law and generates non-vanishing angular momentum of the field. We will discuss the space-time picture that emerges from our analysis and its implications for observables in heavy ion collisions.

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Joseph I. Kapusta, Guangyao Chen, Rainer J. Fries, Yang Li. 2016-04-29. Early Time Dynamics of Gluon Fields in High Energy Nuclear Collisions. https://doi.org/10.1016/j.nuclphysa.2016.01.013

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