The microscopic description of heavy-ion reactions at low beam energies is achieved within hadronic transport approaches. In this article a new approach called ``Simulating Many Accelerated Strongly interacting Hadrons'' (SMASH) introduced and applied to study the production nonstrange particles in ${E}_{\mathrm{kin}}=0.4A--2A$ GeV. First, model described including details about collision criterion, initial conditions resonance formation decays. To validate approach, equilibrium properties...

Non-Abelian plasma instabilities play a crucial role in the nonequilibrium dynamics of weakly coupled quark-gluon plasma, and they importantly modify standard perturbative bottom-up thermalization scenario heavy-ion collisions. Using auxiliary-field formulation hard-loop effective theory, we study numerically real-time evolution an anisotropic collisionless Yang-Mills undergoing longitudinal free-streaming expansion. In this first lattice simulation consider most unstable modes,...

We study the ($3+1$)-dimensional evolution of non-Abelian plasma instabilities in presence a longitudinally expanding background hard particles using discretized hard-loop framework. The free streaming dynamically generates momentum-space anisotropic distribution which is unstable to rapid growth chromomagnetic and chromoelectric fields. These fields produce longitudinal pressure that works isotropize system. Extrapolating our results energies probed ultrarelativistic heavy-ion collisions we...

We use holography to analyze relativistic collisions in a one-parameter family of strongly coupled gauge theories with thermal phase transitions. For critical value the parameter, transition is second order, for subcritical values it first and supercritical smooth crossover. extract theory stress tensor from gravitational shock waves on dual geometries. Regardless nature transition, parameter close value, almost all energy projectiles deposited into long-lived, quasistatic blob at...

We study the equilibrium and near-equilibrium properties of a holographic five-dimensional model consisting Einstein gravity coupled to scalar field with non-trivial potential. The dual four-dimensional gauge theory is not conformal and, at zero temperature, exhibits renormalisation group flow between two different fixed points. quantify deviations from conformality both in terms thermodynamic observables bulk viscosity theory. ratio over shear violates Buchel's bound. relaxation...

We use holography to study the spinodal instability of a four-dimensional, strongly-coupled gauge theory with first-order thermal phase transition. place on cylinder in set homogeneous, unstable initial states. The dual gravity configurations are black branes afflicted by Gregory-Laflamme instability. numerically evolve Einstein’s equations follow until system settles down stationary, inhomogeneous brane. states have constant temperature but non-constant energy density. show that time...

We extend our previous analysis of holographic heavy ion collisions in non-conformal theories. provide a detailed description numerical code. study at different energies gauge theories with degrees non-conformality. compare four relaxation times: the hydrodynamization time (when hydrodynamics becomes applicable), EoSization average pressure approaches its equilibrium value), isotropization longitudinal and transverse pressures approach each other) condensate expectation value scalar operator...

We numerically simulate gravitational shock wave collisions in a holographic model dual to non-conformal four-dimensional gauge theory. find two novel effects associated the non-zero bulk viscosity of resulting plasma. First, hydrodynamization time increases. Second, if is large enough then plasma becomes well described by hydrodynamics before energy density and average pressure begin obey equilibrium equation state. discuss implications for quark-gluon created heavy ion collision experiments.

We use holography to develop a physical picture of the real-time evolution spinodal instability four-dimensional, strongly-coupled gauge theory with first-order, thermal phase transition. numerically solve Einstein's equations follow evolution, in which we identify four generic stages: A first, linear stage grows exponentially; second, non-linear peaks and/or domains are formed; third these structures merge; and fourth system finally relaxes static, phase-separated configuration. On gravity...

The formalism of Baier-Dokshitzer-Mueller-Peign\'e-Schiff and Zakharov determines the modifications parton splittings in QCD plasma that arise from medium-induced gluon radiation. Here, we study medium-modifications splitting into a quark--anti-quark pair this BDMPS-Z formalism. We derive compact path-integral formulation resums effects an arbitrary number interactions with medium to leading order $1/N_c^2$ expansion. Analyses $N=1$ opacity saddle point approximations reveal two phenomena:...

A bstract smoking gun signature for a first-order phase transition with negative speed of sound squared $$ {c}_s^2 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>c</mml:mi> <mml:mi>s</mml:mi> <mml:mn>2</mml:mn> </mml:msubsup> </mml:math> is the occurrence spinodal instability. In gauge/gravity duality it corresponds to Gregory-Laflamme type instability, which can be numerically simulated as evolution unstable planar black branes. Making use holography its...

Ever since fast hydrodynamization has been observed in heavy ion collisions the understanding of hot early out-of-equilibrium stage such a topic intense research. We use gauge/gravity duality to model creation strongly coupled Quark-Gluon plasma non-conformal gauge theory. This numerical relativity study is first holographic simulation collision and reveals existence new relaxation channels due presence non-vanishing bulk viscosity. shock wave at different energies theories with degrees...

To achieve an understanding of the thermalization a quark-gluon plasma, starting from QCD without using model assumptions, is formidable task.We study early stage dynamics relativistic heavy-ion collision in framework real-time simulations classical Yang-Mills theory static box with color glass condensate as initial condition.Our generalizes previous one by Fukushima and Gelis SU(2) to realistic case SU(3).We calculate chromo-electric chromo-magnetic energy densities well ratio longitudinal...

We show that the same QCD formalism accounts for suppression of high-p_{T} hadron and jet spectra in heavy-ion collisions predicts medium-enhanced production cc[over ¯] pairs jets. demonstrate this phenomenon, which cannot be accessed by traditional jet-quenching observables, can directly observed using D^{0}D[over ¯]^{0}-tagged jets nuclear collisions.

The formalism of Baier-Dokshitzer-Mueller-Peigné-Schiff and Zakharov determines the modifications parton splittings in QCD plasma that arise from medium-induced gluon radiation. Here, we study medium-modifications splitting into a quark--anti-quark pair this BDMPS-Z formalism. We derive compact path-integral formulation resums effects an arbitrary number interactions with medium to leading order $1/N_c^2$ expansion. Analyses $N=1$ opacity saddle point approximations reveal two phenomena:...

In this proceedings contribution we review recent calculations of the dynamics chromo-Weibel instability in quark gluon plasma.This is present gauge theories with a one-particle distribution function which momentum-space anisotropic local rest frame.The conditions necessary for triggering can be already color-glass-condensate initial state or dynamically generated by rapid longitudinal expansion matter created heavy-ion collision.Using hard-loop framework study case that possesses an...

The standard model of relativistic heavy-ion collisions describes the hadronic collision in four distinct stages: initial Color glass condensate, glasma, quark gluon plasma and finally hot hadron gas. Exploring transition from at first Lorentz contracted sheets hadrons, color to thermal QCD matter is core this work. study anisotropically expanding plasmas shows that non-Abelian isotropize fast enough thanks chromo-Weibel instability. In recent work we find filamentation instabilities SU(3)...

To achieve an understanding of the thermalization a quark-gluon plasma, starting from QCD without using model assumptions, is formidable task. We study early stage dynamics relativistic heavy ion collision in framework real time simulations classical Yang-Mills theory static box with color glass condensate as initial condition. Our generalizes previous one by Fukushima and Gelis SU(2) to realistic case SU(3). calculate chromo-electric chromo-magnetic energy densities well ratio longitudinal...