BGU Physics Department logo

Fluid-Gravity correspondence and its application to Quark Gluon Plasma

Michael Lublinsky

One of the most intriguing and fundamental questions is a formation of Quark Ggluon Plasma (QGP). Experimentally, QGP is created in the heavy ion collisions. A quest for QGP is the driving force behind two major experimental programs, one at the Relativistic Heavy Ion Collider (RHIC) and another one at the LHC.

Among most striking recent discoveries is the observation made at the RHIC that QGP produced there at temperatures about twice the QCD critical temperature is in fact strongly coupled. The  RHIC data  indicate that QGP at not too high temperatures behaves like a nearly perfect fluid with relativistic hydrodynamics being an appropriate description of the observed phenomena. Remarkably, gauge theories at strong coupling can be studied using the AdS/CFT duality: from the string theory point of view, QGP is holographically dual to weakly coupled string theory in the 5-dimensional  Anti-de-Sitter (AdS) Black Hole background metric.  Many interesting phenomena relevant for heavy ion collisions can be learn from the (super) gravity approximation to the string theory. In particular by studying graviton`s absorption into the AdS Black Hole within Einstein`s general relativity, one can learn a great deal about dissipative processes taking place in QGP.

Quantum Chromo-Dynamics at high energies

Michael Lublinsky

We have entered the fascinating era of the Large Hadron Collider: the initial proton and heavy
ion collisions are already underway. Heavy ion collisions provide the unique possibility of
creating and studying a new state of matter, known as quark gluon plasma, at energy densities
and temperatures similar to those of the early Universe at \(10^{-5}\) seconds after the Big Bang.
The microscopic theory describing the structure of protons and nuclei is the theory of strong
interactions, know as Quantum ChromoDynamics (QCD). Even though the fundamental theory
is known, it is extremely dicult to deduce from the QCD results of collision processes. This is
due to the high level of complexity of the theory involving mutual interactions between gluons,
the "photons" of strong interactions. When probed at very high energies, heavy nuclei, and
even protons, appear as very dense clouds of gluons. The main objective of this proposal is to
develop the theory of high energy collisions of dense gluonic objects, using rst principle QCD
calculation and apply it to experimental data on heavy ion collisions at the LHC.