scholarly journals Investigating the “kink” plot as a signal of the onset of deconfinement

2018 ◽  
Vol 57 (4) ◽  
Author(s):  
Michał Naskręt
Keyword(s):  
Early Stage ◽  
System Size ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Hadronic Matter ◽  
Proton Synchrotron ◽  
Super Proton Synchrotron ◽  
Central Collisions ◽  
The Mean ◽  
Onset Of Deconfinement

One of the physics goals of the NA61/SHINE collaboration at the CERN Super Proton Synchrotron is to study the phase diagram of hadronic matter. To this end, a series of heavy ion collision measurements are performed. It is believed that above a certain collision energy and system size a phase transition between the hadronic matter and quark–gluon plasma occurs. A number of observables have been developed to determine which of the phases was created at the early stage of the collision. This report discusses the dependence of the ratio of the mean number of produced pions to the mean number of wounded nucleons on the Fermi energy measure. For comparison with other measurements this is often presented in the form of the “kink” plot. This plot is presented enriched with preliminary results for 40Ar+45Sc central collisions at 13A, 19A, 30A, 40A, 75A and 150A GeV/c beam momenta. The results are finally compared to data from other experiments.

scholarly journals Spectra and mean multiplicities of $$\pi ^{-}$$ in central $${}^{40}$$Ar+$${}^{45}$$Sc collisions at 13A, 19A, 30A, 40A, 75A and 150$$A\,\text{ Ge }\text{ V }\!/\!\textit{c}$$ beam momenta measured by the NA61/SHINE spectrometer at the CERN SPS

2021 ◽  
Vol 81 (5) ◽  
Author(s):  
A. Acharya ◽  
H. Adhikary ◽  
K. K. Allison ◽  
E. V. Andronov ◽  
T. Antićić ◽  
...  
Keyword(s):  
Particle Production ◽  
System Size ◽  
Hadronic Matter ◽  
Transverse Mass ◽  
Proton Synchrotron ◽  
Inverse Slope ◽  
Super Proton Synchrotron ◽  
Inverse Slope Parameter ◽  
The Mean ◽  
Momentum Transverse

AbstractThe physics goal of the strong interaction program of the NA61/SHINE experiment at the CERN Super Proton Synchrotron (SPS) is to study the phase diagram of hadronic matter by a scan of particle production in collisions of nuclei with various sizes at a set of energies covering the SPS energy range. This paper presents differential inclusive spectra of transverse momentum, transverse mass and rapidity of $$\pi ^{-}$$ π -  mesons produced in central$${}^{40}$$ 40 Ar+$${}^{45}$$ 45 Sc collisions at beam momenta of 13A, 19A, 30A, 40A, 75A and 150$$A\,\text{ Ge }\text{ V }\!/\!\textit{c}$$ A Ge V / c . Energy and system size dependence of parameters of these distributions – mean transverse mass, the inverse slope parameter of transverse mass spectra, width of the rapidity distribution and mean multiplicity – are presented and discussed. Furthermore, the dependence of the ratio of the mean number of produced pions to the mean number of wounded nucleons on the collision energy was derived. The results are compared to predictions of several models.

scholarly journals Measurements of $$\pi ^-$$ production in $$^7$$Be + $$^9$$Be collisions at beam momenta from 19A to 150$$A\,\text{ GeV }\!/\!c$$ in the NA61/SHINE experiment at the CERN SPS

2020 ◽  
Vol 80 (10) ◽  
Author(s):  
A. Acharya ◽  
H. Adhikary ◽  
A. Aduszkiewicz ◽  
K. K. Allison ◽  
E. V. Andronov ◽  
...  
Keyword(s):  
Particle Production ◽  
Nucleon Nucleon ◽  
Particle Identification ◽  
Hadronic Matter ◽  
Transverse Mass ◽  
Proton Synchrotron ◽  
Super Proton Synchrotron ◽  
The Mean ◽  
Onset Of Deconfinement ◽  
Formula Method

AbstractThe NA61/SHINE collaboration studies at the CERN Super Proton Synchrotron (SPS) the onset of deconfinement in hadronic matter by the measurement of particle production in collisions of nuclei with various sizes at a set of energies covering the SPS energy range. This paper presents results on inclusive double-differential spectra and mean multiplicities of $$\pi ^{-}$$ π - mesons produced in the 5% most central$$^7$$ 7 Be + $$^9$$ 9 Be collisions at beam momenta of 19A, 30A, 40A, 75A and 150$$A\,\text{ GeV }\!/\!c$$ A GeV / c obtained by the so-called $$h^-$$ h - method which does not require any particle identification. The shape of the transverse mass spectra differs from the shapes measured in central Pb + Pb collisions and inelastic p+p interactions. The normalized width of the rapidity distribution decreases with increasing collision energy and is in between the results for inelastic nucleon–nucleon and central Pb + Pb collisions. The mean multiplicity of pions per wounded nucleon in central$$^7$$ 7 Be + $$^9$$ 9 Be collisions is close to that in central Pb + Pb collisions up to 75$$A\,\text{ GeV }\!/\!c$$ A GeV / c . However, at the top SPS energy the result lies between those for nucleon–nucleon and Pb + Pb interactions. The results are discussed in the context of predictions for the onset of deconfinement at the CERN SPS collision energies.

scholarly journals PHOTON PRODUCTION IN RELATIVISTIC NUCLEAR COLLISIONS AT SPS AND RHIC ENERGIES

2004 ◽  
Vol 19 (31) ◽  
pp. 5351-5358 ◽  
Author(s):  
SIMON TURBIDE ◽  
RALF RAPP ◽  
CHARLES GALE
Keyword(s):  
Form Factors ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Nucleon Nucleon ◽  
Proton Synchrotron ◽  
Relativistic Heavy Ion Collider ◽  
Super Proton Synchrotron ◽  
Strange Meson ◽  
Nuclear Collisions ◽  
Relativistic Nuclear Collisions

Chiral Lagrangians are used to compute the production rate of photons from the hadronic phase of relativistic nuclear collisions. Special attention to the role of the a1 pseudovector is paid. Calculations that include strange meson reactions, form factors, the use of consistent vector spectral densities, the emission from a quark-gluon plasma, and primordial nucleon-nucleon collisions reproduce the photon spectra measured at the Super Proton Synchrotron (SPS). Some predictions for the Relativistic Heavy Ion Collider (RHIC) are made.

Phenomenological analysis of rapidity distribution of negative pions in central 12C+12C collisions at $\sqrt{s_{nn}} = 3.14\, {\rm GeV}$

2015 ◽  
Vol 24 (06) ◽  
pp. 1550049 ◽  
Author(s):  
Khusniddin K. Olimov ◽  
Qasim Ali ◽  
Mahnaz Q. Haseeb ◽  
Atif Arif ◽  
Sagdulla L. Lutpullaev ◽  
...  
Keyword(s):  
Center Of Mass ◽  
Heavy Ion ◽  
High Energy ◽  
Proton Synchrotron ◽  
Relativistic Heavy Ion Collider ◽  
Super Proton Synchrotron ◽  
Central Collisions ◽  
Ion Collisions ◽  
Initial Assumption ◽  
Rapidity Distributions

Various aspects of the simple phenomenological model, the grand combinational model (GCM), proposed earlier for the systematic description of the center-of-mass (cm) rapidity distributions of different particles produced in high energy heavy ion collisions, were analyzed. The values of GCM parameters were extracted from fitting the cm rapidity distributions of the negative pions in 12 C +12 C collisions at [Formula: see text] both in the experiment and using Modified FRITIOF Model. The GCM parameters extracted for the central 12 C +12 C collisions were compared with those obtained in central Pb + Pb collisions at super proton synchrotron (SPS) and alternating gradient synchrotron (AGS) energies between [Formula: see text] and [Formula: see text] and in central Au + Au collisions at Relativistic heavy ion collider (RHIC) energies between [Formula: see text] and [Formula: see text]. The plausible physical interpretations for the GCM parameters were given. The initial assumption that the parameter β of GCM should be zero for symmetric systems with identical colliding nuclei was validated. The parameter γ of GCM was deduced to follow an approximate asymptotic behavior (γ → 0 as [Formula: see text] at very large cm energies, and γ ≅ 0 could possibly be related to complete dehadronization of the whole collision system, along with attaining its maximum possible energy density, in central collisions of identical nuclei. The behavior of cm energy dependence of γ suggested that it could possibly be sensitive to deconfinement phase transition.

scholarly journals Phase diagram of strongly interacting matter: the last 20 years at the CERN SPS

2020 ◽  
Vol 229 (22-23) ◽  
pp. 3507-3516
Author(s):  
Marek Gazdzicki
Keyword(s):  
Phase Diagram ◽  
Present Theory ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Director General ◽  
Proton Synchrotron ◽  
Super Proton Synchrotron ◽  
Nuclear Collisions ◽  
Strongly Interacting ◽  
Relativistic Nuclear Collisions

AbstractTwenty years ago, on February 10, 2000, the CERN Director General Luciano Maiani announced: The combined data coming from the seven experiments on CERN’s Heavy Ion programme have given a clear picture of a new state of matter. This result verifies an important prediction of the present theory of fundamental forces between quarks. This report briefly reviews studies of the phase diagram of strongly interacting matter with relativistic nuclear collisions at the CERN Super Proton Synchrotron which followed the CERN’s press release on the quark-gluon plasma discovery. An attempt to formulate priorities for future measurements at the CERN SPS closes the paper. The report is dedicated to David Blaschke who celebrated his 60th birthday in 2019. David’s contribution to the studies presented here was very significant.

scholarly journals Latest Results from the NA61/SHINE Experiment

KnE Energy ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 188 ◽  
Author(s):  
D T Larsen
Keyword(s):  
Critical Point ◽  
Energy Dependence ◽  
System Size ◽  
Beam Momentum ◽  
Strong Interactions ◽  
Proton Synchrotron ◽  
Momentum Range ◽  
Super Proton Synchrotron ◽  
Hadron Spectra ◽  
Onset Of Deconfinement

The NA61/SHINE experiment at the CERN Super Proton Synchrotron is pursuing a rich programme on strong interactions, which covers the study of the onset of deconfinement and aims to discover the critical point of strongly interacting matter by performing an energy and system-size scan over the full CERN SPS beam momentum range. So far the scans of p+p, p+Pb, Be+Be, and Ar+Sc interactions have been completed, samples of Pb+Pb data at three energies have already been taken and Xe+La collisions will be registered this year. Results from the different reactions are now emerging, in particular the energy dependence of hadron spectra and yields as well as fluctuations. This contribution presents status and preliminary results from this effort, as well as an outlook for future extensions of the strong interactions programme.

Study the early stage of heavy ion collisions with direct photons

2014 ◽  
Vol 29 ◽  
pp. 1460230 ◽  
Author(s):  
Fu-Ming Liu ◽  
Sheng-Xu Liu
Keyword(s):  
Collective Motion ◽  
Early Stage ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Transverse Momentum Spectrum ◽  
Direct Photons ◽  
Ion Collisions ◽  
Phenix Collaboration ◽  
Early Beginning ◽  
Hadronic Data

Based on the modelling of the collective motion in AuAu collisions at [Formula: see text] at centrality 0-20% and 20-40% and PbPb collisions at [Formula: see text] at centrality 0-40% with a 3+1D event-averaged ideal hydrodynamics constrained with hadronic data, we study the transverse momentum spectrum and elliptic flow of direct photons and find that the recent direct photon data from both PHENIX collaboration at RHIC and ALICE collaboration at LHC favour an early beginning of collective expansion (τ0 < 0.6 fm/c) and a late formation of quark gluon plasma (τ ~ 2 fm/c).

scholarly journals A Review onϕMeson Production in Heavy-Ion Collision

2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
Md. Nasim ◽  
Vipul Bairathi ◽  
Mukesh Kumar Sharma ◽  
Bedangadas Mohanty ◽  
Anju Bhasin
Keyword(s):  
Hadron Collider ◽  
Center Of Mass ◽  
Meson Production ◽  
Dense Matter ◽  
Heavy Ion ◽  
Experimental Program ◽  
Proton Synchrotron ◽  
Relativistic Heavy Ion Collider ◽  
Super Proton Synchrotron ◽  
Strangeness Enhancement

The main aim of the relativistic heavy-ion experiment is to create extremely hot and dense matter and study the QCD phase structure. With this motivation, experimental program started in the early 1990s at the Brookhaven Alternating Gradient Synchrotron (AGS) and the CERN Super Proton Synchrotron (SPS) followed by Relativistic Heavy Ion Collider (RHIC) at Brookhaven and recently at Large Hadron Collider (LHC) at CERN. These experiments allowed us to study the QCD matter from center-of-mass energies (sNN) 4.75 GeV to 2.76 TeV. Theϕmeson, due to its unique properties, is considered as a good probe to study the QCD matter created in relativistic collisions. In this paper we present a review on the measurements ofϕmeson production in heavy-ion experiments. Mainly, we discuss the energy dependence ofϕmeson invariant yield and the production mechanism, strangeness enhancement, parton energy loss, and partonic collectivity in nucleus-nucleus collisions. Effect of later stage hadronic rescattering on elliptic flow (v2) of proton is also discussed relative to corresponding effect onϕmesonv2.

REVIEW OF RAPIDITY DENSITY DISTRIBUTIONS IN HEAVY-ION INDUCED INTERACTIONS AT RELATIVISTIC ENERGIES

1995 ◽  
Vol 04 (03) ◽  
pp. 477-536 ◽  
Author(s):  
MADAN M. AGGARWAL ◽  
STEN I.A. GARPMAN
Keyword(s):  
Quark Gluon Plasma ◽  
Charged Particles ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Projectile Energy ◽  
Density Distributions ◽  
Rapidity Density ◽  
Model Predictions ◽  
Deconfinement Phase Transition ◽  
Onset Of Deconfinement

Violent interactions among colliding nuclei ultimately provide the suitable conditions for creating new and hitherto unexplored phenomena like color rope and quark-gluon plasma formation. The systemmatics achieved so far in pseudorapidity and density distributions of charged particles emitted from relativistic nucleus-nucleus collisions is reviewed and comparisons to model predictions are made. Data from both emulsion and counter experiments are utilized and the dependence of the angular spectra on projectile energy, centrality measured by means of forward charge or enegy flow, and on the projectile/target masses are reported. For a few central events, energy densities of the hot overlap zone are estimated to be beyond onset of deconfinement phase transition.

scholarly journals An estimate of the thermodynamic pressure in high-energy collisions

2015 ◽  
Vol 30 (07) ◽  
pp. 1550027 ◽  
Author(s):  
Abdel Nasser Tawfik
Keyword(s):  
Energy Density ◽  
Chemical Potential ◽  
Lattice Energy ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
High Energy ◽  
Order Moment ◽  
Particle Multiplicity ◽  
The Mean ◽  
Thermodynamic Pressure

We introduce a novel approach to estimate the thermodynamic pressure from heavy-ion collisions based on recently measured higher-order moments of particle multiplicities by the STAR experiment. We start with fitting the experimental results in the most-central collisions. Then, we integrate them back to lower ones. For example, we find that the first-order moment, the mean multiplicity, is exactly reproduced from the integral of variance, the second-order moment. Therefore, the zeroth-order moment, the thermodynamic pressure, can be estimated from the integral of the mean multiplicity. The possible comparison between such a kind of pressure (deduced from the integral of particle multiplicity) and the lattice pressure and the relating of Bjorken energy density to the lattice energy density are depending on lattice QCD at finite baryon chemical potential and first-principle estimation of the formation time of the quark–gluon plasma (QGP).

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