Related papers: Testing the collectivity in large and small collid…
Collective flow has been found to be similar between small colliding systems ($p$ $+$ $p$ and $p$ $+$ A collisions) and large colliding systems (peripheral A $+$ A collisions) at the CERN Large Hadron Collider. In order to study the…
We review recent developments in the theoretical description and understanding of multi-particle correlation measurements in collisions of small projectiles (p/d/$^3$He) with heavy nuclei (Au, Pb) as well as proton+proton collisions. We…
Measurements of multi-particle correlations in the collisions of small systems such as $p+p$, $p/d/^3He+A$ show striking similarity to the observations in heavy ion collisions. A number of observables measured in the high multiplicity…
Signatures of collectivity, including azimuthally anisotropic and radial flow as well as characteristic hadrochemical dependencies, have been observed since long in (ultra)relativistic nucleus-nucleus collisions. They underpin the…
Collective flow of the final-state hadrons observed in ultrarelativistic heavy-ion collisions or even in smaller systems formed in high-multiplicity pp and p/d/$^3$He-nucleus collisions is one of the most important diagnostic tools to probe…
Collective effects are reviewed for collisions of various systems - from proton-proton to heavy ion - in wide energy range. In proton-proton interactions studies of hadron jets devote to the better understanding of some basic features of…
We report on recent progress in understanding multiparticle correlations in small systems from the initial state. First, we consider a proof-of-principle parton model, which we use to demonstrate that many of the multiparticle correlations…
The observation of long-range collective correlations for particles emitted in high-multiplicity pp and pPb collisions has opened up new opportunities of investigating novel high-density QCD phenomena in small colliding systems. We review…
Features of collectivity observed in high energy A+A collision systems at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC) imply a strongly coupled quark gluon plasma (QGP) that flows. One defining feature of…
Collective behaviour has been observed in hadronic measurements of high multiplicity proton+lead collisions at the Large Hadron Collider (LHC), as well as in (proton, deuteron, helium-3)+gold collisions at the Relativistic Heavy-Ion…
Elliptic flow and Number of Constituent Quarks scaling provide crucial insights into the underlying dynamics and degrees of freedom in heavy-ion collisions. This article provides some insights on the transition from hadronic to partonic…
The presence of correlations between particles significantly separated in pseudorapidity in proton-proton and proton-nucleus collisions has raised questions about whether collective effects are observed in small collision systems as well as…
We present the first full (3+1)D dynamical simulations of ultra-peripheral Pb+Pb collisions at the Large Hadron Collider. Extrapolating from p+Pb collisions, we explore whether a quasi-real photon $\gamma^*$ interacting with the lead…
The field of heavy ion physics is at a crossroads in understanding experimental signatures of collectivity in small collision systems, p + p and p(d/3He) + A, at RHIC and the LHC. A wealth of data obtained in the latter class of asymmetric…
The collective phenomena are observed not only in heavy ion collisions, but also in the proton-nucleus and in high-multiplicity $pp$ collisions. The latest results from this area obtained in ATLAS are presented. In $p$+Pb collisions the…
The striking resemblance of high multiplicity proton-proton (pp) collisions at the LHC to heavy ion collisions challenges our conventional wisdom on the formation of the Quark-Gluon Plasma (QGP). A consistent explanation of the collectivity…
We present the first study of collectivity inside jets with high charged multiplicity $N^j_{\rm ch}$ in proton-proton collisions at the Large Hadron Collider. By incorporating final-state partonic and hadronic interactions through cascade…
The bulk motion of nuclear matter at the ultra-high temperatures created in heavy-ion collisions at the Relativistic Heavy Ion Collider and the Large Hadron Collider is well described in terms of nearly inviscid hydrodynamics, thereby…
A new subevent cumulant method was recently developed, which can significantly reduce the non-flow contributions in long-range correlations for small systems compared to the standard cumulant method. In this work, we study multi-particle…
Deciphering the origin of collective phenomena in small colliding systems is one of contemporary focuses in heavy-ion physics. It entails penetrating the barrier between two previously separated research topics:…