scholarly journals Nuclear Physics at the Energy Frontier: Recent Heavy Ion Results from the Perspective of the Electron Ion Collider

Universe ◽  
2019 ◽  
Vol 5 (5) ◽  
pp. 98
Author(s):  
Astrid Morreale
Keyword(s):  
Nuclear Physics ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Hadron Structure ◽  
Proton Proton ◽  
Fundamental Properties ◽  
Protons And Neutrons ◽  
Visible Matter ◽  
Energy Frontier ◽  
Selection Of

Quarks and gluons are the fundamental constituents of nucleons. Their interactions rather than their mass are responsible for 99 % of the mass of all visible matter in the universe. Measuring the fundamental properties of matter has had a large impact on our understanding of the nucleon structure and it has given us decades of research and technological innovation. Despite the large number of discoveries made, many fundamental questions remain open and in need of a new and more precise generation of measurements. The future Electron Ion Collider (EIC) will be a machine dedicated to hadron structure research. It will study the content of protons and neutrons in a largely unexplored regime in which gluons are expected to dominate and eventually saturate. While the EIC will be the machine of choice to quantify this regime, recent surprising results from the heavy ion community have begun to exhibit similar signatures as those expected from a regime dominated by gluons. Many of the heavy ion results that will be discussed in this document highlight the kinematic limitations of hadron–hadron and hadron–nucleus collisions. The reliability of using as a reference proton–proton (pp) and proton–ion (pA) collisions to quantify and disentangle vacuum and Cold Nuclear Matter (CNM) effects from those proceeding from a Quark Gluon Plasma (QGP) may be under question. A selection of relevant pp and pA results which highlight the need of an EIC will be presented.

ULTRARELATIVISTIC NUCLEAR PHYSICS: FROM BECOMING TO BEING

1989 ◽  
Vol 04 (15) ◽  
pp. 3717-3757 ◽  
Author(s):  
W. M. GEIST
Keyword(s):  
Phase Transition ◽  
Quark Gluon Plasma ◽  
Nuclear Physics ◽  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Plasma Properties ◽  
Ion Collisions

Basic theoretical ideas on a phase transition in heavy ion collisions to a thermalized plasma of free quarks and gluons are outlined. Major experiments are then described which made use of oxygen and sulphur beams with moderate (BNL) or high (CERN) momenta. Representative results pertaining to both average event features and quark-gluon plasma properties are discussed in some detail. This review addresses also interested non-specialists.

STAR Heavy-ion results

2020 ◽  
pp. 2040007
Author(s):  
David Tlusty
Keyword(s):  
Phase Diagram ◽  
Nuclear Physics ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Relativistic Heavy Ion Collider ◽  
Qcd Phase Diagram ◽  
Ion Collisions ◽  
Dense Nuclear Matter ◽  
Star Experiment ◽  
Future Plans

The exploration of the Quantum Chromodynamics (QCD) phase diagram has been one of the main drivers of contemporary nuclear physics. Heavy-ion collisions provide a powerful tool to explore phase structures of strongly interacting hot and dense nuclear matter called Quark–Gluon Plasma (QGP). The Relativistic Heavy Ion Collider (RHIC) is uniquely suited to map the QCD phase diagram by varying the energy of collisions, as well as nuclei species. These proceedings discuss the most recent results from the STAR experiment at RHIC and future plans.

scholarly journals Ion Colliders

2014 ◽  
Vol 07 ◽  
pp. 49-76 ◽  
Author(s):  
Wolfram Fischer ◽  
John M. Jowett
Keyword(s):  
Nuclear Physics ◽  
Collision Energy ◽  
Hadron Collider ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
High Energy ◽  
Heavy Nuclei ◽  
Relativistic Heavy Ion Collider ◽  
Polarized Protons ◽  
Ion Species

High energy ion colliders are large research tools in nuclear physics for studying the quark–gluon–plasma (QGP). The collision energy and high luminosity are important design and operational considerations. The experiments also expect flexibility with frequent changes in the collision energy, detector fields, and ion species. Ion species range from protons, including polarized protons in RHIC, to heavy nuclei like gold, lead, and uranium. Asymmetric collision combinations (such as protons against heavy ions) are also essential. For the creation, acceleration, and storage of bright intense ion beams, limits are set by space charge, charge change, and intrabeam scattering effects, as well as beam losses due to a variety of other phenomena. Currently, there are two operating ion colliders: the Relativistic Heavy Ion Collider (RHIC) at BNL and the Large Hadron Collider (LHC) at CERN.

scholarly journals Resummation of Jet Shapes and Extracting Properties of the Quark-Gluon Plasma

2015 ◽  
Vol 37 ◽  
pp. 1560047 ◽  
Author(s):  
Yang-Ting Chien
Keyword(s):  
Quark Gluon Plasma ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Jet Quenching ◽  
Effective Theory ◽  
Proton Proton ◽  
Power Corrections ◽  
Soft Collinear Effective Theory ◽  
Jet Shapes ◽  
Good Agreement

Understanding the properties of the quark-gluon plasma (QGP) that is produced in ultra-relativistic nucleus-nucleus collisions has been one of the top priorities of the heavy ion program at the LHC. Energetic jets are produced and subsequently quenched in the collisions. Such jet quenching phenomena provide promising tools to probe the medium properties by studying the modification of jets due to the medium interactions. Significant modifications of jet shapes have been measured. In this talk we focus on the calculation of jet shapes in both proton-proton and lead-lead collisions using soft-collinear effective theory (SCET), with Glauber gluon interactions in the medium. Large logarithms in jet shapes are resummed at next-to-leading logarithmic (NLL) accuracy by the renormalization-group evolution between hierarchical jet scales. The medium interactions contribute as power corrections, and we calculate the modification of jet shapes at leading order in opacity with the static QGP model. Preliminary results are presented with good agreement with the recent CMS jet shape measurements.

scholarly journals Quark–gluon soup — The perfectly liquid phase of QCD

2015 ◽  
Vol 30 (02) ◽  
pp. 1530011 ◽  
Author(s):  
Ulrich Heinz
Keyword(s):  
Nuclear Physics ◽  
National Laboratory ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Brookhaven National Laboratory ◽  
Precise Determination ◽  
Relativistic Heavy Ion Collisions ◽  
Strongly Coupled ◽  
Ion Collisions

At temperatures above about 150 MeV and energy densities exceeding 500 MeV/fm3, quarks and gluons exist in the form of a plasma of free color charges that is about 1000 times hotter and a billion times denser than any other plasma ever created in the laboratory. This quark–gluon plasma (QGP) turns out to be strongly coupled, flowing like a liquid. About 35 years ago, the nuclear physics community started a program of relativistic heavy-ion collisions with the goal of producing and studying QGP under controlled laboratory conditions. This article recounts the story of its successful creation in collider experiments at Brookhaven National Laboratory and CERN and the subsequent discovery of its almost perfectly liquid nature, and reports on the recent quantitatively precise determination of its thermodynamic and transport properties.

scholarly journals Small systems at the LHC

2018 ◽  
Vol 171 ◽  
pp. 11003 ◽  
Author(s):  
Roberto Preghenella
Keyword(s):  
High Energy Physics ◽  
Heavy Ion ◽  
High Energy ◽  
Proton Proton ◽  
Small Systems ◽  
Proton Collisions ◽  
Strangeness Enhancement ◽  
Proton Proton Collisions ◽  
Energy Physics ◽  
Selection Of

In these proceedings, I report on a selection of recent LHC results in small systems from ALICE [1], ATLAS [2] and CMS [3] experiments. Due to the fact that the investigation of QCD in small systems at high multiplicity is becoming an increasingly large subject, interesting the heavy-ion community and more in general the high-energy physics community, not all the related topics can be discussed in this paper. The focus will be given to some of the measurements addressing the physics of collective phenomena in small systems and to the recent results on strangeness enhancement in proton-proton collisions. The reader must be informed that a large number of interesting results did not find space in the discussion reported here.

scholarly journals Vector boson tagged jets and jet substructure

2018 ◽  
Vol 172 ◽  
pp. 05006
Author(s):  
Ivan Vitev
Keyword(s):  
Transverse Momentum ◽  
Heavy Ion Collisions ◽  
Vector Boson ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Jet Substructure ◽  
Proton Proton ◽  
Jet Production ◽  
Ion Collisions ◽  
Jet Shapes

In these proceedings, we report on recent results related to vector boson-tagged jet production in heavy ion collisions and the related modification of jet substructure, such as jet shapes and jet momentum sharing distributions. Z0-tagging and γ-tagging of jets provides new opportunities to study parton shower formation and propagation in the quark-gluon plasma and has been argued to provide tight constrains on the energy loss of reconstructed jets. We present theoretical predictions for isolated photon-tagged and electroweak boson-tagged jet production in Pb+Pb collisions at √sNN = 5.02 TeV at the LHC, addressing the modification of their transverse momentum and transverse momentum imbalance distributions. Comparison to recent ATLAS and CMS experimental measurements is performed that can shed light on the medium-induced radiative corrections and energy dissipation due to collisional processes of predominantly quark-initiated jets. The modification of parton splitting functions in the QGP further implies that the substructure of jets in heavy ion collisions may differ significantly from the corresponding substructure in proton-proton collisions. Two such observables and the implication of tagging on their evaluation is also discussed.

scholarly journals HEND: A DATABASE FOR HIGH-ENERGY NUCLEAR DATA

2007 ◽  
Vol 16 (07n08) ◽  
pp. 2370-2374
Author(s):  
DAVID BROWN ◽  
RAMONA VOGT
Keyword(s):  
Nuclear Physics ◽  
Theoretical Models ◽  
Nuclear Data ◽  
Heavy Ion ◽  
High Energy ◽  
Published Data ◽  
Proton Proton ◽  
Experimental Database ◽  
Periodic Data ◽  
On Line

We propose to develop a high-energy heavy-ion experimental database and make it accessible to the scientific community through an on-line interface. The database will be searchable and cross-indexed with relevant publications, including published detector descriptions. It should eventually contain all published data from older heavy-ion programs such as the Bevalac, AGS, SPS and FNAL fixed-target programs, as well as published data from current programs at RHIC and new facilities at GSI (FAIR), KEK/Tsukuba and the LHC collider. This data includes all proton-proton, proton-nucleus to nucleus-nucleus collisions as well as other relevant systems and all measured observables. Such a database would have tremendous scientific payoff as it makes systematic studies easier and allows simpler benchmarking of theoretical models to a broad range of experiments. To enhance the utility of the database, we propose periodic data evaluations and topical reviews. These reviews would provide an alternative and impartial mechanism to resolve discrepancies between published data from rival experiments and between theory and experiment. Since this database will be a community resource, it requires the high-energy nuclear physics community's financial and manpower support.

scholarly journals Investigating high energy proton proton collisions with a multi-phase transport model approach based on PYTHIA8 initial conditions

2021 ◽  
Vol 81 (8) ◽  
Author(s):  
Liang Zheng ◽  
Guang-Hui Zhang ◽  
Yun-Fan Liu ◽  
Zi-Wei Lin ◽  
Qi-Ye Shou ◽  
...  
Keyword(s):  
Transport Model ◽  
Initial Conditions ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
High Energy ◽  
High Multiplicity ◽  
Pp Collisions ◽  
Proton Proton ◽  
Transverse Momentum Spectra ◽  
Model Approach

AbstractThe 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 phenomena in pp will help us to understand the mechanism that leads to the QGP-like signals in small systems. In this study, we introduce a transport model approach connecting the initial conditions provided by PYTHIA8 with subsequent AMPT rescatterings to study the collective behavior in high energy pp collisions. The multiplicity dependence of light hadron productions from this model is in reasonable agreement with the pp $$\sqrt{s}=13$$ s = 13 TeV experimental data. It is found in the comparisons that both the partonic and hadronic final state interactions are important for the generation of the radial flow feature of the pp transverse momentum spectra. The study also shows that the long range two particle azimuthal correlation in high multiplicity pp events is sensitive to the proton sub-nucleon spatial fluctuations.

scholarly journals Effect of magnetic screening mass on the diffusion of heavy quarks

2021 ◽  
Author(s):  
Mahfuzur Rahaman ◽  
Santosh K. Das ◽  
Jan-e Alam ◽  
Sabyasachi Ghosh
Keyword(s):  
Diffusion Coefficients ◽  
Dense Matter ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Heavy Quarks ◽  
Proton Proton ◽  
Ion Collisions ◽  
Magnetic Screening ◽  
The Impact ◽  
And Diffusion

The drag and diffusion coefficients of heavy quarks propagating through quark–gluon plasma (QGP) have been estimated by shielding the infra-red divergences using electric and magnetic screening masses. The electric-type screening in perturbative quantum chromodynamics (pQCD) has been widely studied and used in evaluating the diffusion coefficient of heavy quarks (HQs). The impact of magnetic screening on diffusion coefficients of HQs is not studied before to the best of our knowledge. We explore the effect of magnetic screening mass on the drag and diffusion coefficients of HQs and found it to be non-negligible. Therefore, the effect of magnetic screening should be taken into consideration to characterize hot and dense matter formed in the collisions of nuclei at ultra-relativistic energies. We estimate the suppression of heavy flavored mesons in heavy ion collisions compared to proton+proton collisions at high transverse momenta and found that the suppression is less with the inclusion of magnetic screening. The value of the magnetic screening mass is not known exactly because of its nonperturbative nature. Moreover, it may not be possible to single out the effect of magnetic mass because of the uncertainties in other parameters involved in the diffusion process of HQs. Still it is important to include the effects of magnetic screening because of its physical origin in QCD.

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