Coupling constant corrections in a holographic model of heavy ion collisions with nonzero baryon number density

Journal Article · 10 December 2019 · Journal of High Energy Physics (Online)

DOI: https://doi.org/10.1007/JHEP12(2019)093 · OSTI ID:1637348

Folkestad, Asmund ^[1]; Grozdanov, Sašo ^[2]; Rajagopal, Krishna ^[2]; van der Schee, Wilke ^[3]

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1. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States), Center for Theoretical Physics
2. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
3. Utrecht Univ. (The Netherlands)

Sufficiently energetic collisions of heavy ions result in the formation of a droplet of a strongly coupled liquid state of QCD matter known as quark-gluon plasma. By using gauge-gravity duality (holography), a model of a rapidly hydrodynamizing and thermal- izing process like this can be constructed by colliding sheets of energy density moving at the speed of light and tracking the subsequent evolution. In this work, we consider the dual gravitational description of such collisions in the most general bulk theory with a four-derivative gravitational action containing a dynamical metric and a gauge field in five dimensions. Introducing the bulk gauge field enables the analysis of collisions of sheets which carry nonzero “baryon” number density in addition to energy density. Introducing the four-derivative terms enables consideration of such collisions in a gauge theory with finite gauge coupling, working perturbatively in the inverse coupling. While the dynamics of energy and momentum in the presence of perturbative inverse-coupling corrections has been analyzed previously, here we are able to determine the effect of such finite coupling corrections on the dynamics of the density of a conserved global charge, which we take as a model for the dynamics of nonzero baryon number density. In accordance with expectations, as the coupling is reduced we observe that after the collisions less baryon density ends up stopped at mid-rapidity and more of it ends up moving near the lightcone.

• Research Organization: Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• Grant/Contract Number: SC0011090
• OSTI ID: 1637348
• Journal Information: Journal of High Energy Physics (Online), Journal Name: Journal of High Energy Physics (Online) Journal Issue: 12 Vol. 2019; ISSN 1029-8479
• Publisher: Springer BerlinCopyright Statement
• Country of Publication: United States
• Language: English