scholarly journals Measurements of the Υ Meson Production in Au + Au Collisions by the STAR Experiment

Proceedings ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 46
Author(s):  
Oliver Matonoha
Keyword(s):  
Theoretical Calculations ◽  
Meson Production ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Relativistic Heavy Ion Collisions ◽  
Decay Channels ◽  
Ion Collisions ◽  
200 Gev ◽  
Star Experiment ◽  
Colour Screening

In ultra-relativistic heavy-ion collisions, creation of a novel state of matter, the quark-gluon plasma (QGP), has been observed. Suppressed production of quarkonia, caused by the colour screening of the binding force, has been proposed as a direct evidence of the QGP formation. At RHIC energies, other phenomena such as the regeneration and co-mover absorption, are expected to have a small effect for the bottomonium family, which makes Υ a cleaner probe of the screening effect compared to the J / ψ meson. In these proceedings, the latest measurements of the Υ production suppression in Au + Au collisions at s NN = 200 GeV via the di-muon and di-electron decay channels by the STAR experiment at RHIC are presented and compared with data from the LHC and theoretical calculations. Moreover, Υ production measurements in p + p and p + Au collisions are also reported, providing a baseline and a quantification of the cold nuclear matter effects, respectively.

scholarly journals HEAVY-QUARKONIA IN THE STAR EXPERIMENT

2007 ◽  
Vol 16 (09) ◽  
pp. 2952-2955
Author(s):  
◽  
MAURO R. COSENTINO
Keyword(s):  
Excited States ◽  
Quark Gluon Plasma ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Relativistic Heavy Ion Collisions ◽  
Heavy Quarkonium ◽  
Medium Temperature ◽  
Preliminary Results ◽  
Ion Collisions ◽  
Star Experiment

Heavy Quarkonium states modifications in relativistic heavy ion collisions have been of great interest since the proposal by Matsui and Satz of J/ψ suppression as a signature of Quark-Gluon Plasma (QGP) formation. Recent studies suggest that the excited states χc, ψ(2 S ) and ϒ(3 S ) melt sequentially1,2 and the amount of observed suppression depends on the state and medium conditions. Therefore, this suppression pattern may be used as a probe of the medium temperature. In this work we present preliminary results on the charmonium and bottomnium measurements performed by the STAR experiment at RHIC for p + p and Cu + Cu collisions at [Formula: see text].

scholarly journals Review of QCD, cosmological phase transitions, QGP, heavy quark meson production enhancement and suppression

2017 ◽  
Vol 32 (15) ◽  
pp. 1730008 ◽  
Author(s):  
Leonard S. Kisslinger
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Heavy Quark ◽  
Quark Gluon Plasma ◽  
Meson Production ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Relativistic Heavy Ion Collisions ◽  
Ion Collisions ◽  
Present Universe

This review of the quantum chromodynamics (QCD), the early universe cosmological phase transition from the quark–gluon plasma (QGP) to our present universe (QCDPT), relativistic heavy ion collisions (RHIC) which can produce the QGP, the possible detection of the QGP produced by the production of mixed hybrid heavy quark mesons. We also review the recent studies of the production of mixed heavy quark hybrids via RHIC and heavy quark meson suppression in p-Pb and Pb–Pb collisions.

scholarly journals Anisotropic (v1 and v2) Flow in Relativistic Heavy-Ion Collisions at Energies between 4 GeV and 200 GeV

2018 ◽  
Vol 191 ◽  
pp. 05004
Author(s):  
L.V. Bravina ◽  
Yu. Kvasiuk ◽  
S.Yu. Sivoklokov ◽  
O. Vitiuk ◽  
E.E. Zabrodin
Keyword(s):  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Relativistic Heavy Ion Collisions ◽  
High Energies ◽  
Ion Collisions ◽  
200 Gev ◽  
Basic Features ◽  
String Models ◽  
Freeze Out

Basic features of directed and elliptic flows of identified hadrons in heavy-ion collisions at intermediate and high energies are considered within two transport string models, UrQMD and QGSM. Both models indicate changing of the sign of proton directed flow at midrapidity from antiflow to normal flow with decreasing energy of collisions. The origin of this effect is traced to hadron rescattering in baryon-rich remnants of the colliding nuclei. To distinguish the effect of rescattering from the flow softening caused by creation of quark-gluon plasma one has to compare heavy-ion and light-ion collisions at the same energy. Both directed and elliptic flows at midrapidity are formed within t = 10-12 fm/c. The differences in the development of elliptic flows of mesons and baryons are found at high energies. These differences can be explained by dissimilar freeze-out conditions, thus suggesting simultaneous study of particle collective flow and freeze-out.

scholarly journals Studies of Heavy Flavor Jets Using D0-Hadron Correlations in Azimuth and Pseudorapidity in Au Au Collisons at 200 GeV at the STAR Experiment

Proceedings ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 34
Author(s):  
Alexander Jentsch
Keyword(s):  
Early Stage ◽  
Heavy Ion ◽  
Azimuthal Anisotropy ◽  
Relativistic Heavy Ion Collisions ◽  
Strong Interactions ◽  
Heavy Flavor ◽  
Angular Correlations ◽  
Ion Collisions ◽  
200 Gev ◽  
Star Experiment

Heavy flavor (HF) quarks (charm, bottom) are important probes of the medium produced in relativistic heavy-ion collisions because they are formed in the early stage and propagate throughout the lifetime of the system. HF-meson spectra and azimuthal anisotropy ( v 2 ) measurements have been reported by experiments at RHIC and the LHC, and they suggest strong interactions of HF quarks with the medium. D 0 -hadron correlations on relative pseudorapidity and azimuth ( Δ η , Δ ϕ ) provide a method for disentangling correlation structures on ( Δ η , Δ ϕ )—allowing for separation of structures related to jets and bulk phenomena directly, with the D 0 serving as a proxy for a charm jet. In these proceedings, we present 2D D 0 -hadron angular correlations as a function of centrality in Au + Au collisions at s N N = 200 GeV. These data reveal a jet-like, peaked structure at ( Δ η , Δ ϕ ) = (0, 0) (near-side), and a Δ η -independent azimuthal harmonic modulation. Here, we focus on the evolution of the near-side peak’s yield and widths on ( Δ η , Δ ϕ ) as a function of centrality and compare them to results from light flavor correlations.

scholarly journals ϕ Meson Measurements at RHIC with the PHENIX Detector

2018 ◽  
Vol 171 ◽  
pp. 13004
Author(s):  
Murad Sarsour
Keyword(s):  
Meson Production ◽  
Heavy Ion ◽  
Relativistic Heavy Ion Collisions ◽  
Nuclear Medium ◽  
Dense Medium ◽  
Interaction Cross Section ◽  
Medium Effects ◽  
Ion Collisions ◽  
Wide Range ◽  
200 Gev

The measurement of ϕ mesons provides key information on the phase of the hot and dense medium created in the relativistic heavy ion collisions. It has a relatively small hadronic interaction cross section and is sensitive to the increase of strangeness (strangeness enhancement), a phenomenon associated with soft particles in bulk matter. Measurements in the dilepton channels are especially interesting since leptons interact only electromagnetically, thus carrying the information from their production phase directly to the detector. Measurements in different nucleus-nucleus collisions allow us to perform a systematic study of the nuclear medium effects on ϕ meson production. The PHENIX detector provides the capabilities to measure the ϕ meson production in a wide range of transverse momentum and rapidity to study these effects. In this proceeding, we present measurements of the ϕ mesons in a variety of collision systems at [see formula in PDF] = 200 GeV. In case of small systems, the data are compared with AMPT calculations to study the various cold nuclear medium effects involved in ϕ meson production.

scholarly journals Quarkonium measurements in heavy-ion collisions with the STAR experiment

2018 ◽  
Vol 171 ◽  
pp. 18015
Author(s):  
Xinjie Huang
Keyword(s):  
Transverse Momentum ◽  
Nuclear Matter ◽  
Heavy Ion Collisions ◽  
Theoretical Calculations ◽  
Heavy Ion ◽  
Matter Effects ◽  
Nuclear Modification ◽  
Ion Collisions ◽  
Star Experiment ◽  
Nuclear Modification Factors

In these proceedings, we present the latest measurements of J/ψ and ϒ by the STAR experiment. The J/ψ and ϒ production measured in p+p collisions provide new baselines for similar measurements in Au+Au collisions, while the measurements in p+Au collisions can help quantify the cold nuclear matter effects. The J/ψ υ2 is measured in both U+U and Au+Au collisions to place constraints on the amount of J/ψ arising from recombination of deconfined charm and anti-charm pairs. Furthermore, the nuclear modification factors for ground and excited ϒ states as a function of transverse momentum and centrality are presented, and compared to those measured at the LHC as well as to theoretical calculations.

scholarly journals Highlights from PHENIX at RHIC

2018 ◽  
Vol 171 ◽  
pp. 01003
Author(s):  
Rachid Nouicer
Keyword(s):  
Heavy Quark ◽  
Heavy Ion Collisions ◽  
Meson Production ◽  
Heavy Ion ◽  
Relativistic Heavy Ion Collisions ◽  
Dense Medium ◽  
Heavy Flavor ◽  
Theoretical Understanding ◽  
Rapidity Region ◽  
Ion Collisions

Hadrons conveying strange quarks or heavy quarks are essential probes of the hot and dense medium created in relativistic heavy-ion collisions. With hidden strangeness, ϕ meson production and its transport in the nuclear medium have attracted high interest since its discovery. Heavy quark-antiquark pairs, like charmonium and bottomonium mesons, are mainly produced in initial hard scattering processes of partons. While some of the produced pairs form bound quarkonia, the vast majority hadronize into particles carrying open heavy flavor. In this context, the PHENIX collaboration carries out a comprehensive physics program which studies the ϕ meson production, and heavy flavor production in relativistic heavy-ion collisions at RHIC. In recent years, the PHENIX experiment upgraded the detector in installing silicon vertex tracker (VTX) at mid-rapidity region and forward silicon vertex tracker (FVTX) at the forward rapidity region. With these new upgrades, the experiment has collected large data samples, and enhanced the capability of heavy flavor measurements via precision tracking. This paper summarizes the latest PHENIX results concerning ϕ meson, open and closed charm and beauty heavy quark production in relativistic heavy-ion collisions. These results are presented as a function of rapidity, energy and system size, and their interpretation with respect to the current theoretical understanding.

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