scholarly journals Correlations of High-pT Hadrons and Jets in ALICE

Universe ◽  
2019 ◽  
Vol 5 (5) ◽  
pp. 124
Author(s):  
Filip Krizek
Keyword(s):  
Energy Transport ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Jet Quenching ◽  
Relativistic Heavy Ion Collisions ◽  
High Transverse Momentum ◽  
Subtraction Method ◽  
Final State ◽  
Ion Collisions ◽  
Quenching Phenomenon

There are two prominent experimental signatures of quark–gluon plasma creation in ultra-relativistic heavy-ion collisions: the jet quenching phenomenon and the azimuthal-momentum space-anisotropy of final-state particle emission. Recently, the latter signature was also observed in lighter collision systems such as p–Pb or pp. This raises a natural question of whether in these systems, the observed collectivity is also accompanied by jet quenching. In this paper, we overview ALICE measurements of the jet quenching phenomenon studied using semi-inclusive distributions of track-based jets recoiling from a high-transverse momentum ( p T ) hadron trigger in Pb–Pb and p–Pb collisions at LHC energies. The constructed coincidence observable, the per trigger normalized yield of associated recoil jets, is corrected for the complex uncorrelated jet background, including multi-partonic interactions, using a data-driven statistical subtraction method. In the p–Pb data, the observable was measured in events with different underlying event activity and was utilized to set an upper limit on the average medium-induced out-of-cone energy transport for jets with resolution parameter R = 0.4 . The associated jet momentum shift was found to be less than 0.4 GeV/c at 90% confidence.

JET CONVERSIONS IN QGP AND SUPPRESSION OF IDENTIFIED HADRONS

2007 ◽  
Vol 16 (07n08) ◽  
pp. 1930-1936 ◽  
Author(s):  
WEI LIU ◽  
CHE MING KO ◽  
BEN-WEI ZHANG
Keyword(s):  
Transverse Momentum ◽  
Quark Gluon Plasma ◽  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Relativistic Heavy Ion Collisions ◽  
High Transverse Momentum ◽  
Ion Collisions ◽  
Conversion Rates ◽  
Gluon Jets

A gluon or quark jet traversing through a quark-gluon plasma can be converted into a quark or gluon jet through scatterings with thermal partons. Their conversion rates due to two-body elastic and inelastic scattering as well as scatterings involving gluon radiation are evaluated in the lowest order in Quantum Chromodynamics (QCD). Including both energy loss and conversions of quark and gluon jets in the expanding quark-gluon plasma produced in relativistic heavy ion collisions, we find a net conversion of quark jets to gluon jets. This reduces the difference between the nuclear modification factors for quark and gluon jets in central heavy ion collisions and thus enhances the p/π+ and [Formula: see text] ratios at high transverse momentum. Using the larger QCD coupling constant from lattice QCD calculations than that given by the perturbative QCD further enhances the net quark to gluon jet conversion rate, leading to a closer similarity between these ratios at high transverse momentum in central Au + Au collisions at [Formula: see text] and in p + p collisions at same energy as observed in experiments.

scholarly journals Anisotropic flow and jet quenching in relativistic nuclear collisions

2015 ◽  
Vol 24 (02) ◽  
pp. 1530001 ◽  
Author(s):  
Guang-You Qin
Keyword(s):  
Dense Matter ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
High Energy ◽  
Jet Quenching ◽  
Relativistic Heavy Ion Collisions ◽  
Anisotropic Flow ◽  
Nuclear Collisions ◽  
Ion Collisions ◽  
Relativistic Nuclear Collisions

The exploration of the strong-interaction matter under extreme conditions is one of the main goals of relativistic heavy-ion collisions. We provide some of the main results on the novel properties of quark-gluon plasma, with particular focus given to the strong collectivity and the color opaqueness exhibited by such hot and dense matter produced in high-energy nuclear collisions at RHIC and the LHC.

scholarly journals Jet structure in heavy ion collisions

2015 ◽  
Vol 24 (11) ◽  
pp. 1530012 ◽  
Author(s):  
J.-P. Blaizot ◽  
Y. Mehtar-Tani
Keyword(s):  
Heavy Ion Collisions ◽  
Turbulent Transport ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Jet Quenching ◽  
Relativistic Heavy Ion Collisions ◽  
Ion Collisions ◽  
Parton Cascade ◽  
Probabilistic Nature ◽  
Jet Structure

We review recent theoretical developments in the study of the structure of jets that are produced in ultra relativistic heavy ion collisions. The core of the review focusses on the dynamics of the parton cascade that is induced by the interactions of a fast parton crossing a quark–gluon plasma. We recall the basic mechanisms responsible for medium induced radiation, underline the rapid disappearance of coherence effects, and the ensuing probabilistic nature of the medium induced cascade. We discuss how large radiative corrections modify the classical picture of the gluon cascade, and how these can be absorbed in a renormalization of the jet quenching parameter [Formula: see text]. Then, we analyze the (wave)-turbulent transport of energy along the medium induced cascade, and point out the main characteristics of the angular structure of such a cascade. Finally, color decoherence of the in-cone jet structure is discussed. Modest contact with phenomenology is presented towards the end of the review.

scholarly journals Time reclustering for jet quenching studies

2021 ◽  
Vol 81 (6) ◽  
Author(s):  
Liliana Apolinário ◽  
André Cordeiro ◽  
Korinna Zapp
Keyword(s):  
Hadron Collider ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Jet Quenching ◽  
Time Structure ◽  
Relativistic Heavy Ion Collisions ◽  
Relativistic Heavy Ion Collider ◽  
Ion Collisions ◽  
Physics Program ◽  
Unique Potential

AbstractThe physics program of ultra-relativistic heavy-ion collisions at the Large Hadron Collider (LHC) and Relativistic Heavy-Ion Collider (RHIC) has brought a unique insight into the hot and dense QCD matter created in such collisions, the Quark-Gluon Plasma (QGP). Jet quenching, a collection of medium-induced modifications of the jets’ internal structure that occur through their development in dense QCD matter, has a unique potential to assess the time structure of the produced medium. In this work, we perform an exploratory study to identify jet reclustering tools that can potentiate future QGP tomographic measurements with jets at current energies. Our results show that by using the inverse of formation time to obtain the jet clustering history, one can identify more accurately the time structure of QCD emissions inside jets, even in the presence of jet quenching.

scholarly journals JET CONVERSIONS IN QUARK-GLUON PLASMA

2011 ◽  
Vol 20 (07) ◽  
pp. 1641-1645
Author(s):  
CHE MING KO
Keyword(s):  
Quark Gluon Plasma ◽  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Relativistic Heavy Ion Collisions ◽  
High Transverse Momentum ◽  
Ion Collisions ◽  
Conversion Rates ◽  
Gluon Jets ◽  
The Difference

In addition to loosing energy, a quark or gluon jet traversing through a quark-gluon plasma can also be converted to a gluon or quark jet through scattering with the thermal quarks and gluons. Their conversion rates due to two-body elastic [Formula: see text] and inelastic [Formula: see text] scattering have been evaluated in the lowest order in QCD. Including both energy loss and conversions of quark and gluon jets in the expanding quark-gluon plasma produced in relativistic heavy ion collisions, a net conversion of quark jets to gluon jets has been found. This reduces the difference between the nuclear modification factors for quark and gluon jets in heavy ion collisions and thus enhances the ratios of high transverse momentum protons and antiprotons to pions that are produced from the fragmentation of these jets. To account for the observed similar ratios in central Au + Au and p + p collisions at same energy requires, however, a much larger net quark to gluon jet conversion rate than that given by the lowest-order QCD, indicating the importance of higher-order processes and the strongly coupling nature of the quark-gluon plasma in describing the propagation of jets in the quark-gluon plasma.

scholarly journals Characterising Charm Jet Properties with Azimuthal Correlations of D Mesons and Charged Particles with ALICE at the LHC

Proceedings ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 35
Author(s):  
Shyam Kumar for the ALICE Collaboration
Keyword(s):  
Heavy Ion Collisions ◽  
Charm Quark ◽  
Charged Particles ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Relativistic Heavy Ion Collisions ◽  
Pp Collisions ◽  
Final State ◽  
Essential Information ◽  
Ion Collisions

Charm quarks are produced via hard parton scattering in ultra-relativistic heavy-ion collisions, hence are ideal probes to study a possible de-confined state of matter, known as Quark Gluon Plasma (QGP). The angular correlation of a meson containing a charm quark with other charged particles in heavy-ion collisions can help in studying the properties of QGP. Similar studies in pp collisions can give insight about the charm production mechanism while in p-Pb collisions could provide essential information to disentangle final-state QGP-induced modifications from effects caused by cold nuclear matter. In this proceedings, the results are presented for p-Pb collisions at s NN = 5.02 TeV and pp collisions at s = 13 TeV, so far the highest available energy at the LHC. The results are compared with Monte Carlo (MC) simulations using PYTHIA and POWHEG event generators and with pp collision results at s = 7 TeV.

J/ψ PRODUCTION FROM CHARM COALESCENCE IN RELATIVISTIC HEAVY ION COLLISIONS

2007 ◽  
Vol 16 (07n08) ◽  
pp. 2061-2065
Author(s):  
BIN ZHANG
Keyword(s):  
Heavy Ion Collisions ◽  
D Meson ◽  
Charm Quark ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Relativistic Heavy Ion Collisions ◽  
Final State ◽  
Charm Quarks ◽  
Ion Collisions ◽  
Multi Phase

J/ψ production is closely related to the production of the strongly interacting Quark-Gluon Plasma (sQGP) in relativistic heavy ion collisions. To study the effects of charm quark dynamics on J/ψ production, the phase space distributions of charm and anti-charm quarks are generated using A Multi-Phase Transport (AMPT) model. These charm quarks then coalesce into J/ψ particles. The production and flow of J/ψ show strong sensitivity to final state charm interactions. The results are compared to charm quark and D meson results from the AMPT model and recent predictions from other models.

scholarly journals Signatures of QGP at RHIC and the LHC

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
T. Niida ◽  
Y. Miake
Keyword(s):  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
High Energy ◽  
Jet Quenching ◽  
Theoretical Studies ◽  
Debye Screening ◽  
Direct Photons ◽  
Ion Collisions ◽  
Experimental And Theoretical Studies

AbstractThe progress over the 30 years since the first high-energy heavy-ion collisions at the BNL-AGS and CERN-SPS has been truly remarkable. Rigorous experimental and theoretical studies have revealed a new state of the matter in heavy-ion collisions, the quark-gluon plasma (QGP). Many signatures supporting the formation of the QGP have been reported. Among them are jet quenching, the non-viscous flow, direct photons, and Debye screening effects. In this article, selected signatures of the QGP observed at RHIC and the LHC are reviewed.

scholarly journals Probing jet medium interactions via Z(H) + jet momentum imbalances

2020 ◽  
Vol 80 (12) ◽  
Author(s):  
Lin Chen ◽  
Shu-Yi Wei ◽  
Han-Zhong Zhang
Keyword(s):  
Transport Coefficient ◽  
Good Description ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
High Energy ◽  
Jet Quenching ◽  
Quenching Effect ◽  
Nuclear Collisions ◽  
Ion Collisions ◽  
Pqcd Approach

AbstractDifferent types of high energy hard probes are used to extract the jet transport properties of the Quark-Gluon Plasma created in heavy-ion collisions, of which the heavy boson tagged jets are undoubtedly the most sophisticated due to its clean decay signature and production mechanism. In this study, we used the resummation improved pQCD approach with high order correction in the hard factor to calculate the momentum ratio $$x_J$$ x J distributions of Z and Higgs (H) tagged jets. We found that the formalism can provide a good description of the 5.02 TeV pp data. Using the BDMPS energy loss formalism, along with the OSU 2 + 1D hydro to simulate the effect of the medium, we extracted the value of the jet transport coefficient to be around $${\hat{q}}_0=4\sim 8~\text {GeV}^2/\text {fm}$$ q ^ 0 = 4 ∼ 8 GeV 2 / fm by comparing with the Z + jet PbPb experimental data. The H + jet $$x_J$$ x J distribution were calculated in a similar manner in contrast and found to have a stronger Sudakov effect as compared with the Z + jet distribution. This study uses a clean color-neutral boson as trigger to study the jet quenching effect and serves as a complimentary method in the extraction of the QGP’s transport coefficient in high energy nuclear collisions.

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