Related papers: The Ridge, the Glasma and Flow
The CMS collaboration at the LHC has reported a remarkable and unexpected phenomenon in very high-multiplicity high energy proton-proton collisions: a positive correlation between two particles produced at similar azimuthal angles, spanning…
We propose that flow fluctuations have the same origin as transverse momentum fluctuations. The common source of these fluctuations is the spatially inhomogeneous initial state that drives hydrodynamic flow. Longitudinal correlations from…
We present the predictions of a hydrodynamic model for the flow observables recently measured in the highest-multiplicity p+Pb collisions at the LHC. We focus o the ridge phenomenon, which provides an important probe of the long-range…
We present analytic results that describe the gluon field, or glasma, at very early times after a collision of relativistic heavy ions at proper time $\tau=0$. We use a Colour Glass Condensate approach, and perform an expansion in $\tau$.…
We show that an observable fraction of the measured elliptic flow may originate in classical gluon fields at the initial stage of a peripheral high-energy nuclear collision. This mechanism complements the contribution of late stage…
We compute the elliptic flow generated by classical gluon fields in a high energy nuclear collision. The classical gluon fields are described by a typical momentum scale, the saturation scale Lambda_s, which is, for RHIC energies, of the…
Fluctuations in the initial state of heavy-ion collisions are larger at RHIC energy than at LHC energy. This fact can be inferred from recent measurements of the fluctuations of the particle multiplicities and of elliptic flow performed at…
It is claimed that elliptic flow, ridge and alignment are effects of azimuthal asymmetry, which have a common origin evolving with primary energy and stemming from the general structure of field-theoretical matrix elements. It interrelates…
The Color Glass Condensate formalism and its application to high energy heavy ion collisions at RHIC are discussed. We argue that the RHIC data supports the view that the Color Glass Condensate provides the initial conditions for gold-gold…
The observation in small size collision systems, $pp$ and $p$A, of strong correlations with long range in rapidity and a characteristic structure in azimuth, the ridge phenomenon, is one of the most interesting results obtained at the Large…
Since their discovery, fluctuations in the initial state of heavy-ion collisions have been understood as originating mostly from the random positions of nucleons within the colliding nuclei. We consider an alternative approach where all the…
Heavy quarks, which are produced at the earliest stage of relativistic heavy-ion collisions, probe the entire history of the quark-gluon plasma that is created in the collision. Initially the plasma is populated with chromodynamic fields…
The similarities between string percolation and Glasma results are emphasized, special attention being paid to rapidity long range correlations, ridge structure and elliptic flow. As the string density of high multiplicity pp collisions at…
These two lectures concern the Color Glass Condensate and the Glasma. These are forms of matter which might be studied in high energy hadronic collisions. The Color Glass Condensate is high energy density gluonic matter. It constitutes the…
At high energy, the gluon distribution in nuclei reaches large densities and eventually saturates due to recombinations, that play an important role in heavy ion collisions at RHIC and the LHC. The Color Glass Condensate provides a…
In the Color Glass Condensate (CGC) effective field theory, colliding sheets of Colored Glass form a strongly interacting, non-equilibrium state called the Glasma. How Colored Glass shatters to form the Glasma, the properties of the Glasma,…
The Color Glass Condensate is an effective theory description for the small momentum fraction x degrees of freedom in a high energy hadron or nucleus, which can be understood in terms of strong classical gluon fields. We discuss the…
A very recent paper by the CMS collaboration \cite{cms_ridge} has created large discussion in the media, which call it important but did not explain why, in some places even calling it "unundestandable". While it is of course too soon to…
Azimuthal anisotropy in heavy-ion collisions is studied by taking into account the ridges generated by semi-hard scattering of intermediate-momentum partons, which can be sensitive to the initial spatial configuration of the medium in…
We obtain a novel result in QCD for long range rapidity correlations between gluons produced in the collision of saturated high energy hadrons or nuclei. This result, obtained in a high energy factorization framework, provides strong…