Collectivity without plasma in hadronic collisions

Bierlich, Christian; Gustafson, Gösta; Lönnblad, Leif

doi:10.1016/j.physletb.2018.01.069

Cited by 118 publications

(130 citation statements)

References 42 publications

Supporting

Mentioning

126

Contrasting

Order By: Relevance

“…Second, string interactions predicted the collectivity features observed in pp collisions at the LHC [53]. Recently, sophisticated models containing both an enhancement of the string tension due to the overlap of the string colour fields, and repulsion among the strings inspired by lattice results, are able to describe the ridge azimuthal distributions [54], see Fig. 6 left.…”

Section: Multiple Parton Interactionsmentioning

confidence: 88%

“…Besides nPDFs, I have Figure 6. Left plots: two particle azimuthal distributions from the DIPSY model [54] with and without shoving (string repulsion), compared to CMS data. Right plots: two particle azimuthal distributions and second Fourier coefficient in the AMPT model initialised with two strings, with and without parton rescattering [55].…”

Section: Multiple Parton Interactionsmentioning

confidence: 99%

See 1 more Smart Citation

Small collision systems: Theory overview on cold nuclear matter effects

Armesto

2018

EPJ Web Conf.

View full text Add to dashboard Cite

Abstract. Many observables measured at the Relativistic Heavy Ion Collider and the Large Hadron Collider show a smooth transition between proton-proton and protonnucleus collisions (small systems), and nucleus-nucleus collisions (large systems), when represented versus some variable like the multiplicity in the event. In this contribution I review some of the physics mechanisms, named cold nuclear matter effects, that may lead to a collective-like behaviour in small systems beyond the macroscopic description provided by relativistic hydrodynamics. I focus on the nuclear modification of parton densities, single inclusive particle production and correlations. MotivationIn recent years much attention has been devoted in the high-energy physics community to the experimental findings that indicate a smooth transition between "small" collisions systems (proton-proton, pp, and proton-nucleus, pA) and "large" collision systems (nucleus-nucleus, AA). These findings at both the Large Hadron Collider (LHC) and the Relativistic Heavy Ion Collider (RHIC), are particularly striking as some of the involved observables have been traditionally considered as signatures of the creation of deconfined partonic matter close to thermodynamical equilibrium -Quark Gluon Plasma -in high-energy AA collisions. They include (see the review [1]) azimuthal asymmetries of apparent collective nature, thermal-like spectra and baryon/strangeness enhancement at small and intermediate transverse momentum respectively, hadrochemistry, interferometry, quarkonium suppression,. . . , the only exception being jet quenching.While this behaviour was first observed in AA and high-multiplicity pA and pp collisions, the interest in this subject has been increased recently by the observation that azimuthal asymmetries and the ridge structure -two particle correlations whose strength extends through several units of pseudorapidity and is maximum at zero (near side region) and π (back-to-back region) azimuthal angle -can also be observed in pp collisions with multiplicities close to minimum bias [2][3][4]. From the theoretical side, two facts augment the importance of these findings even further: the fact that viscous relativistic hydrodynamics is able to provide a description of such data [5] even if the conditions of large opacity and approximate momentum isotropy seem difficult to fulfil in pp; and the applicability of hydrodynamics in far-from-equilibrium situations that was obtained both at strong [6,7] and weak coupling [8]. Thus, the traditional statement that the success of hydrodynamics clearly indicated the

show abstract

Section: Multiple Parton Interactionsmentioning

confidence: 88%

Section: Multiple Parton Interactionsmentioning

confidence: 99%

Small collision systems: Theory overview on cold nuclear matter effects

Armesto

2018

EPJ Web Conf.

View full text Add to dashboard Cite

show abstract

“…The question which begs to be answered is if such a microscopic model can describe other features usually ascribed to plasma formation, such as flow and jet quenching. Regarding flow, ongoing efforts [27] aim to investigate whether the transverse pressure…”

Section: Discussionmentioning

confidence: 99%

Rope Hadronization and Strange Particle Production

Bierlich

2018

EPJ Web Conf.

Self Cite

View full text Add to dashboard Cite

Abstract. Rope Hadronization is a model extending the Lund string hadronization model to describe environments with many overlapping strings, such as high multiplicity pp collisions or AA collisions. Including effects of Rope Hadronization drastically improves description of strange/non-strange hadron ratios as function of event multiplicity in all systems from e + e − to AA. Implementation of Rope Hadronization in the MC event generators Dipsy and Pythia8 is discussed, as well as future prospects for jet studies and studies of small systems.

show abstract

“…To what extent the hydrodynamics is applicable in small systems is still under debate [18]. The most successful phenomenological models, URQMD, HIJING, NEXSPHERIO, AMPT, PHSD, EPOS, describing the latest results obtained at LHC in pp, p-Pb and Pb-Pb collisions are based on combinations of different approaches for different stages of the collision [19][20][21][22][23][24], while the classical phenomenological models used in particle physics like PYTHIA [25], HERWIG [26], and PHOJET [27] had to implement processes like multiparton interaction, rescattering, color reconnection [28], or a shoving mechanism [29] in order to improve the agreement with the LHC results, especially in the soft sector in pp collisions. In this paper we also present a comparison between pp and Pb-Pb at LHC energies in terms of the dependence of different observables on the …”

Section: Published By the American Physical Society Under The Terms Omentioning

confidence: 99%

Geometrical scaling for energies available at the BNL Relativistic Heavy Ion Collider to those at the CERN Large Hadron Collider

et al. 2018

View full text Add to dashboard Cite

)/S ⊥ does not depend on centrality, at the LHC energies a deviation from a linear behavior is observed towards the most central collisions. The influence of the corona contribution on the observed trends is discussed. The slopes of the p T particle mass dependence and the β T parameter from BGBW fits scale well with √ ( dN dy )/S ⊥ . Similar systematic trends for pp at √ s = 7 TeV are in a good agreement with the ones corresponding to Pb-Pb collisions at √ s NN = 2.76 and 5.02 TeV, pointing to a system-size-independent behavior.

show abstract

Collectivity without plasma in hadronic collisions

Cited by 118 publications

References 42 publications

Small collision systems: Theory overview on cold nuclear matter effects

Small collision systems: Theory overview on cold nuclear matter effects

Rope Hadronization and Strange Particle Production

Geometrical scaling for energies available at the BNL Relativistic Heavy Ion Collider to those at the CERN Large Hadron Collider

Contact Info

Product

Resources

About