scholarly journals PROSPECTS OF SEARCHING FOR (UN)PARTICLES FROM HIDDEN SECTORS USING RAPIDITY CORRELATIONS IN MULTIPARTICLE PRODUCTION AT THE LHC

2009 ◽  
Vol 24 (24) ◽  
pp. 4529-4572 ◽  
Author(s):  
MIGUEL-ANGEL SANCHIS-LOZANO
Keyword(s):  
Heavy Ion ◽  
Gluon Plasma ◽  
New Physics ◽  
Event Shape ◽  
Final State ◽  
Factorial Moments ◽  
Particle Correlation ◽  
Ion Collisions ◽  
Simplifying Assumptions ◽  
The Impact

Most signatures of new physics have been studied on the transverse plane with respect to the beam direction at the LHC where background is much reduced. In this paper we propose the analysis of inclusive longitudinal (pseudo)rapidity correlations among final-state (charged) particles in order to search for (un)particles belonging to a hidden sector beyond the Standard Model, using a selected sample of p–p minimum bias events (applying appropriate off-line cuts on events based on, e.g. minijets, high-multiplicity, event shape variables, high-p⊥ leptons and photons, etc.) collected at the early running of the LHC. To this aim, we examine inclusive and semi-inclusive two-particle correlation functions, forward–backward correlations, and factorial moments of the multiplicity distribution, without resorting to any particular model but under very general (though simplifying) assumptions. Finally, motivated by some analysis techniques employed in the search for quark–gluon plasma in heavy-ion collisions, we investigate the impact of such intermediate (un)particle stuff on the (multi)fractality of parton cascades in p–p collisions, by means of a Lévy stable law description and a Ginzburg–Landau model of phase transitions. Results from our preliminary study seem encouraging for possible dedicated analyses at LHC and Tevatron experiments.

scholarly journals Fluctuating shapes of fireballs in heavy-ion collisions

2019 ◽  
Vol 204 ◽  
pp. 03011
Author(s):  
Boris Tomášik ◽  
Jakub Cimerman ◽  
Renata Kopečná ◽  
Martin Schulc
Keyword(s):  
Quark Gluon Plasma ◽  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Event Shape ◽  
Final State ◽  
Ion Collisions ◽  
Final State Hadron ◽  
Novel Method ◽  
Energy And Momentum

We argue that the energy and momentum deposition from hard partons into quark-gluon plasma induces an important contribution to the final state hadron anisotropies. We also advocate a novel method of Event Shape Sorting which allows one to analyse the azimuthal anisotropies of the fireball dynamics in more detail. The application of the method in femtoscopy is demonstrated.

Collective flow and correlation with higher harmonic event planes

Open Physics ◽  
2012 ◽  
Vol 10 (6) ◽  
Author(s):  
ShinIchi Esumi
Keyword(s):  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
High Energy ◽  
Jet Quenching ◽  
System Response ◽  
Azimuthal Correlation ◽  
Particle Correlation ◽  
Ion Collisions ◽  
Higher Harmonic

AbstractAzimuthal event anisotropy and particle correlation have been used to analyze the collectivity of the system created in the high-energy heavy-ion collisions in order to study the properties of Quark Gluon Plasma (QGP). Higher harmonic event anisotropy is recently recognized to carry the information of initial participant geometrical fluctuation because of the finite number of participating nucleons in heavy-ion collisions. The system response after the collective expansion can be observed as higher harmonic event anisotropy, the n-th harmonic order dependence can be used to further constrain the hydro-dynamical properties of the system. The multi-particle azimuthal correlation with respect to the higher harmonic event plane can be used as a tool to understand the origin of the higher harmonic event anisotropy and its relation to the medium response from the jet-quenching as soft-hard interplay. Recent results on the higher harmonic event anisotropy measurements and an attempt of two-particle correlation analysis with respect to the higher harmonic event planes are discussed.

scholarly journals Correlations in the Initial Conditions of Heavy-Ion Collisions

2020 ◽  
Vol 235 ◽  
pp. 08002 ◽  
Author(s):  
Douglas Wertepny ◽  
Jacquelyn Noronha-Hostler ◽  
Matthew Sievert ◽  
Skandaprasad Rao ◽  
Noah Paladino
Keyword(s):  
Initial Conditions ◽  
Heavy Ion ◽  
Color Glass ◽  
Heavy Nuclei ◽  
Initial State ◽  
Final State ◽  
Microscopic Mechanism ◽  
Ion Collisions ◽  
The Impact ◽  
Initial Geometry

Ultracentral collisions of heavy nuclei, in which the impact parameter is nearly zero, are especially sensitive to the details of the initial state model and the microscopic mechanism for collective flow. In a hydrodynamic “flow” picture, the final state momentum correlations are a direct response to the fluctuating initial geometry, although models of the initial geometry differ widely. Alternatively, dynamical mechanisms based in the color glass condensate (CGC) formalism can naturally lead to many-body correlations with very different systematics. Here we present a calculation of event-by-event elliptic flow in both the hydrodynamic and CGC paradigms and show that they can be qualitatively distinguished in ultracentral collisions of deformed nuclei. Specifically, the multiplicity dependence in such collisions is qualitatively opposite, with the CGC correlations increasing with multiplicity while the hydrodynamic correlations decrease. The consistency of the latter with experimental data on UU collisions appears to rule out a CGC-mediated explanation. We find that these qualitative features also persist in small deformed systems and can therefore be a valuable test of the microscopic physics in that regime. The authors acknowledge support from the US-DOE Nuclear Science Grant No. DE-SC0019175, and the Alfred P. Sloan Foundation, and the Zuckerman STEM Leadership Program.

Transit Times in Lltra-Relativistic Heavy-Ion Collisions

1991 ◽  
Vol 46 (12) ◽  
pp. 1037-1042 ◽  
Author(s):  
G. Wolschin
Keyword(s):  
Heavy Ions ◽  
Heavy Ion Collisions ◽  
Hadron Collider ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Maximum Energy ◽  
Relativistic Heavy Ion Collisions ◽  
Ion Collisions ◽  
Transit Times ◽  
The Impact

Abstract Mean transit times in heavy-ion collisions are calculated as functions of the relativistic incident energy and the impact parameter. As a consequence of special relativity, they become constant in a central collision of O with Pb at T~0.15TeV. Together with a geometrical estimate of the maximum energy densities in the interaction region, it is argued that heavy ions in a large hadron collider may produce a quark-gluon plasma due to the plateau in the transit times at ultra-relativistic energies

QGP SIGNALS AND THE DUAL PARTON MODEL: IS THERMAL EQUILIBRIUM REACHED IN HEAVY ION COLLISIONS?

2005 ◽  
Vol 20 (19) ◽  
pp. 4399-4404
Author(s):  
A. CAPELLA
Keyword(s):  
Thermal Equilibrium ◽  
Final State Interaction ◽  
String Model ◽  
Parton Model ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
State Interaction ◽  
Final State ◽  
Ion Collisions ◽  
Dual Parton Model

Some of the so-called signals of Quark Gluon Plasma (QGP) formation are examined in the framework of a string model, the Dual Parton Model, supplemented with final state interaction. The aim is to determine the strength and duration time of the final state interaction required to describe the data, in order to gain some insight on whether or not the system reaches thermal equilibrium.

scholarly journals Relating Charged Particle Multiplicity to Impact Parameter in Heavy-Ion Collisions at NICA Energies

Particles ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 275-287
Author(s):  
Petr Parfenov ◽  
Dim Idrisov ◽  
Vinh Ba Luong ◽  
Arkadiy Taranenko
Keyword(s):  
Impact Parameter ◽  
Heavy Ion Collisions ◽  
Simulated Data ◽  
Heavy Ion ◽  
Relativistic Heavy Ion Collisions ◽  
Particle Multiplicity ◽  
Charged Particle Multiplicity ◽  
Final State ◽  
Ion Collisions ◽  
The Impact

The size and evolution of the matter created in relativistic heavy-ion collisions strongly depend on collision geometry, defined by the impact parameter. However, the impact parameter cannot be measured directly in an experiment but might be inferred from final state observables using the centrality procedure. We present the procedure of centrality determination for the Multi-Purpose Detector (MPD) at the NICA collider and its performance using the multiplicity of produced charged particles at midrapidity. The validity of the procedure is assessed using the simulated data for Au + Au collisions at sNN = 4–11 GeV.

TWO-PARTICLE CORRELATION IN HEAVY-ION COLLISIONS AT CSR ENERGY

2007 ◽  
Vol 16 (07n08) ◽  
pp. 2200-2204
Author(s):  
JINGBO ZHANG ◽  
QICHUN FENG ◽  
LEI HUO ◽  
WEINING ZHANG
Keyword(s):  
Imaging Technique ◽  
Final State Interaction ◽  
Relativistic Quantum ◽  
Heavy Ion ◽  
Quantum Molecular Dynamics ◽  
Dynamics Model ◽  
Final State ◽  
Particle Correlation ◽  
Ion Collisions ◽  
The Relationship

The predictions of the two-particle correlation by using the relativistic quantum molecular dynamics model are presented for the heavy-ion reactions at HIRFL-CSR energy. The two-proton correlation function with the final state interaction is calculated with the Lednicky code for the U + U collisions at beam energy 520 A MeV. Applying the imaging technique, the relationship between the freeze-out spatial distributions and the results of correlation femtoscopy is investigated. We find that one can reliably reconstruct the source functions from the two-particle correlation functions with ignoring the degree of space-momentum correlations at this energy. The results are useful to the designing the hadron detector at CSR.

scholarly journals Dilepton creation based on an analytic hydrodynamic solution

Open Physics ◽  
2014 ◽  
Vol 12 (2) ◽  
Author(s):  
Máté Csanád ◽  
Levente Krizsán
Keyword(s):  
Time Evolution ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
High Energy ◽  
Direct Photon ◽  
Relativistic Hydrodynamics ◽  
Final State ◽  
Mass Distributions ◽  
Ion Collisions ◽  
Hydrodynamic Solution

AbstractHigh-energy collisions of various nuclei, so called “Little Bangs” are observed in various experiments of heavy ion colliders. The time evolution of the strongly interacting quark-gluon plasma created in heavy ion collisions can be described by hydrodynamical models. After expansion and cooling, the hadrons are created in a freeze-out. Their distribution describes the final state of this medium. To investigate the time evolution one needs to analyze penetrating probes, such as direct photon or dilepton observables, as these particles are created throughout the evolution of the medium. In this paper we analyze an 1+3 dimensional analytic solution of relativistic hydrodynamics, and we calculate dilepton transverse momentum and invariant mass distributions. We investigate the dependence of dilepton production on time evolution parameters, such as emission duration and equation of state. Using parameters from earlier fits of this model to photon and hadron spectra, we compare our calculations to measurements as well. The most important feature of this work is that dilepton observables are calculated from an exact, analytic, 1+3D solution of relativistic hydrodynamics that is also compatible with hadronic and direct photon observables.

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.

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.

Sign in / Sign up

Export Citation Format

Share Document