scholarly journals Tubular Initial Conditions and Ridge Formation

2013 ◽  
Vol 2013 ◽  
pp. 1-10
Author(s):  
M. S. Borysova ◽  
O. D. Borysov ◽  
Iu. A. Karpenko ◽  
V. M. Shapoval ◽  
Yu. M. Sinyukov
Keyword(s):  
Initial Conditions ◽  
Initial Energy ◽  
Transverse Plane ◽  
Tubular Structures ◽  
Superdense Matter ◽  
Energy Density Distribution ◽  
Particle Correlations ◽  
Initial Energy Density ◽  
Hydrodynamic Evolution ◽  
Angular Interval

The 2D azimuth and rapidity structure of the two-particle correlations in relativistic A+A collisions is altered significantly by the presence of sharp inhomogeneities in superdense matter formed in such processes. The causality constraints enforce one to associate the long-range longitudinal correlations observed in a narrow angular interval, the so-called (soft) ridge, with peculiarities of the initial conditions of collision process. This study's objective is to analyze whether multiform initial tubular structures, undergoing the subsequent hydrodynamic evolution and gradual decoupling, can form the soft ridges. Motivated by the flux-tube scenarios, the initial energy density distribution contains the different numbers of high density tube-like boost-invariant inclusions that form a bumpy structure in the transverse plane. The influence of various structures of such initial conditions in the most central A+A events on the collective evolution of matter, resulting spectra, angular particle correlations andvn-coefficients is studied in the framework of the hydrokinetic model (HKM).

Initial energy density distribution in high energy heavy ion reactions

1988 ◽  
Vol 214 (4) ◽  
pp. 657-659 ◽  
Author(s):  
G.N. Fowler ◽  
F.S. Navarra ◽  
M. Plümer ◽  
A. Vourdas ◽  
R.M. Weiner ◽  
...  
Keyword(s):  
Energy Density ◽  
Density Distribution ◽  
Heavy Ion ◽  
High Energy ◽  
Initial Energy ◽  
Energy Density Distribution ◽  
Heavy Ion Reactions ◽  
Initial Energy Density

scholarly journals Influence of tubular initial conditions on two-particle correlations

2011 ◽  
Vol 38 (12) ◽  
pp. 124123 ◽  
Author(s):  
R P G Andrade ◽  
F Gardim ◽  
F Grassi ◽  
Y Hama ◽  
W L Qian
Keyword(s):  
Initial Conditions ◽  
Particle Correlations

scholarly journals Modeling Cosmic Expansion, and Possible Inflation, as a Thermodynamic Heat Engine

2019 ◽  
Vol 74 (2) ◽  
pp. 153-162 ◽  
Author(s):  
Christopher Pilot
Keyword(s):  
Positive Curvature ◽  
Heat Engine ◽  
Initial Energy ◽  
Closed Universe ◽  
Observable Universe ◽  
Cosmic Expansion ◽  
Initial Energy Density ◽  
Inflationary Phase ◽  
Background Temperature ◽  
Traditional Sense

AbstractAssuming a closed universe with slight positive curvature, cosmic expansion can be modeled as a heat engine where we define the “system,” collectively, as those regions of space within the observable universe, which will later evolve into voids. We identify the “surroundings,” collectively, as those pockets of space that will eventually develop into matter-filled galaxies, clusters, superclusters, and filament walls. Using this model, we can find the energy needed for cosmic expansion using basic thermodynamic principles and show that cosmic expansion had as its origin a finite initial energy density, pressure, volume, and temperature. Inflation in the traditional sense, with the inflaton field, may also not be required. We also argue that homogeneities and inhomogeneities in the WMAP temperature profile are attributable to quantum mechanical fluctuations about a fixed background temperature in the initial isothermal expansion phase of the cycle, which we identify with inflation. Fluctuations in temperature can cause certain regions of space to lose heat while other regions will absorb that heat. The voids, being those regions that absorb the heat, will expand, thereby leaving slightly cooler temperatures for the surroundings, where matter will later congregate. Upon freeze-out, this could produce the observed WMAP signature with its associated inhomogeneity. Finally, using the uncertainty relation, we estimate that the temperature and time for formation of WMAP inhomogeneities occurred at roughly 3.02 × 1027 K and 2.54 × 10−35 s, respectively, after first initiation of volume expansion. This is in line with current estimates for the end of the inflationary epoch. The heat input in the inflationary phase is calculated as roughly Q = 1.81 × 1094 J (photons only); the collective void volume increases by a factor of only 5.65. The bubble voids in the observable universe increase in size from about 0.046 to 0.262 m3 within this inflationary period in our model.

scholarly journals Initial Energy Density of √ s = 7 and 8 TeV p+p Collisions at the LHC

2016 ◽  
Author(s):  
Mate Csanad ◽  
Tamas Csorgo ◽  
Ze-Fang Jiang ◽  
Chun-Bin Yang
Keyword(s):  
Energy Density ◽  
Critical Energy ◽  
High Energy ◽  
Initial Energy ◽  
High Multiplicity ◽  
Initial Energy Density ◽  
Critical Energy Density ◽  
High Energy Collisions ◽  
8 Tev ◽  
Natural Description

Accelerating, exact, explicit and simple solutions of relativistic hydrodynamics allow for a simple and natural description of highly relativistic p+p collisions. These solutions yield a finite rapidity distribution, thus they lead to an advanced estimate of the initial energy density of high energy collisions. We show that such an advanced estimate yields an initial energy density in $\sqrt{s}=7$ and 8 TeV p+p collisions at LHC around or above the critical energy density from lattice QCD, and a corresponding initial temperature above the critical temperature from QCD and the Hagedorn temperature. This suggests that the collision energy of the LHC corresponds to a large enough initial energy density to create a non-hadronic perfect fluid even in pp collisions. %We also show, that several times the %critical energy density may have been reached in high multiplicity events, hinting at a non-hadronic medium created in %high multiplicity $\sqrt{s}=7$ and 8 TeV p+p collisions.

scholarly journals Distinctive features of the structure of current sheets formed in plasma in three-dimensional magnetic configurations with an X line (a review)

2021 ◽  
Vol 9 (6) ◽  
pp. 464-478
Author(s):  
Anna Frank
Keyword(s):  
Longitudinal Magnetic Field ◽  
Initial Conditions ◽  
Three Dimensional ◽  
Limited Range ◽  
Transverse Plane ◽  
Plasma Current ◽  
Initial Value ◽  
Distinctive Features ◽  
Current Sheets ◽  
Guide Field

A review is presented on experimental results related to investigation of distinctive features of the structure and evolution of plasma current sheets formed in three dimensional (3D) magnetic configurations with an X line, in the presence of a longitudinal magnetic field component (guide field) directed along the X line. It is shown that formation of a plasma current sheet results in enhancement of the guide field within the sheet. The excessive guide field is maintained by plasma currents that flow in the transverse plane relative to the main current in the sheet. As a result, the structure of the currents becomes three-dimensional. Increasing the initial value of the guide field brings about a decrease of compression into the sheet of both the electric current and plasma. This effect is caused by changing the pres- sure balance in the sheet when an excessive guide field appears in it. Deformation of plasma current sheets in 3D magnetic configurations, namely, an appearance of asymmetric and tilted sheets, results from excitation of the Hall currents and their interaction with the guide field. It is shown that the formation of current sheets in 3D magnetic configurations with an X line is possible in a relatively wide, but limited range of initial conditions

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