Search results for "Heavy Ion"
showing 10 items of 314 documents
Rate Equation Network for Baryon Production in High Energy Nuclear Collisions
2003
We develop and solve a network of rate equations for the production of baryons and anti-baryons in high energy nuclear collisions. We include all members of the baryon octet and decuplet and allow for transformations among them. This network is solved during a relativistic 2+1 hydrodynamical expansion of the of the hot matter created in the collision. As an application we compare to the number of protons, lambdas, negative cascades, and omega baryons measured at mid-rapidity in central collisions of gold nuclei at 65 GeV per nucleon at the Relativistic Heavy Ion Collider (RHIC).
Glueball enhancement by color deconfinement
2007
5 pages, 4 figures.-- PACS nrs.: 14.80.-j; 24.80.+y; 25.75.Nq.-- ISI Article Identifier: 000245333000063.-- ArXiv pre-print available at: http://arxiv.org/abs/hep-ph/0609219
Jet evolution in a dense medium: event-by-event fluctuations and multi-particle correlations
2017
International audience; We study the gluon distribution produced via successive medium-induced branchings by an energetic jet propagating through a weakly-coupled quark-gluon plasma. We show that under suitable approximations, the jet evolution is a Markovian stochastic process, which is exactly solvable. For this process, we construct exact analytic solutions for all the n-point correlation functions describing the gluon distribution in the space of energy [M. A. Escobedo, E. Iancu, Event-by-event fluctuations in the medium-induced jet evolution, JHEP 05 (2016) 008. arXiv: arXiv:1601.03629 , doi: http://dx.doi.org/10.1007/JHEP05(2016)008 , M. A. Escobedo, E. Iancu, Multi-particle correlati…
The percolation phase transition and statistical multifragmentation in finite systems
2020
The cumulant ratios up to fourth order of the $Z$ distributions of the largest fragment in spectator fragmentation following $^{107,124}$Sn+Sn and $^{124}$La+Sn collisions at 600 MeV/nucleon have been investigated. They are found to exhibit the signatures of a second-order phase transition established with cubic bond percolation and previously observed in the ALADIN experimental data for fragmentation of $^{197}$Au projectiles at similar energies. The deduced pseudocritical points are found to be only weakly dependent on the $A/Z$ ratio of the fragmenting spectator source. The same holds for the corresponding chemical freeze-out temperatures of close to 6 MeV. The experimental cumulant dist…
Facility for thermal helium desorption (THDS) measurements
1995
Abstract We describe a thermal helium desorption spectrometer, built at the Department of Physics, University of Jyvaskyla, which will be used in investigations of crystal defects generated by keV range heavy ion bombardment. The helium desorption method and its requirements are reviewed briefly. The structure of the facility itself is presented in detail. The efficiency and the operation of the apparatus is discussed.
Determination of electronic stopping powers of 0.05–1MeV/u 131Xe ions in C-, Ni- and Au-absorbers with calorimetric low temperature detectors
2017
Abstract A new experimental system for precise determination of electronic stopping powers of heavy ions has been set up at the accelerator laboratory of the University of Jyvaskyla. The new setup, combining an established B-ToF system and an array of calorimetric low temperature detectors (CLTDs), has been used for the determination of electronic stopping powers of 0.05–1 MeV/u 131Xe ions in carbon, nickel and gold. Thereby advantage of the improved linearity and energy resolution of CLTDs as compared to the previously used ionization detector was taken to reduce energy calibration errors and to increase sensitivity for the energy loss determination, in particular at very low energies. The…
New experimental molecular stopping cross section data of Al2O3, for heavy ions
2014
Abstract Molecular stopping cross section data of Al2O3, for heavy ions of 12C, 16O, 28Si, 35Cl, 79Br within the energy range of 0.01–1.0 MeV/nucleon were measured. Both direct transmission and bulk analysis methods were applied. Stopping cross sections were calculated both with the SRIM and MSTAR codes. Evaluation and intercomparison of the new data with the calculated and previously measured ones are reported in this paper.
In situ and postradiation analysis of mechanical stress in Al2O3:Cr induced by swift heavy-ion irradiation
2010
Abstract Optical spectroscopy and TEM techniques have been applied to study the radiation damage and correlated mechanical stresses in Al2O3 and Al2O3:Cr single crystals induced by (1–3) MeV/amu Kr, Xe and Bi ion irradiation. Mechanical stresses were evaluated in situ using a piezospectroscopic effect through the shift of the respective lines in ionoluminescence spectra. It was found that dose dependence of the stress level for Xe and Bi ions, when ionization energy loss exceeds the threshold of damage formation via electronic excitations, exhibits several alternate stages showing the build-up and relaxation of stresses. The beginning of relaxation stages is observed at fluences associated …
Measurement of Z0-boson production at large rapidities in Pb–Pb collisions at √sNN = 5.02 TeV
2018
The production of Z0 bosons at large rapidities in Pb–Pb collisions at √sNN=5.02TeV is reported. Z0 candidates are reconstructed in the dimuon decay channel (Z0→μ+μ−), based on muons selected with pseudo-rapidity −4.020GeV/c. The invariant yield and the nuclear modification factor, RAA, are presented as a function of rapidity and collision centrality. The value of RAA for the 0–20% central Pb–Pb collisions is 0.67±0.11(stat.)±0.03(syst.)±0.06(corr. syst.), exhibiting a deviation of 2.6σ from unity. The results are well-described by calculations that include nuclear modifications of the parton distribution functions, while the predictions using vacuum PDFs deviate from data by 2.3σ in the 0–…
Measurement of dielectron production in central Pb-Pb collisions at √sNN = 2.76 TeV
2019
The first measurement of dielectron ( e + e − ) production in central ( 0 – 10 % ) Pb–Pb collisions at √ s NN = 2.76 TeV at the LHC is presented. The dielectron invariant-mass spectrum is compared to the expected contributions from hadron decays in the invariant-mass range 0 < m ee < 3.5 GeV / c 2 . The ratio of data and the cocktail of hadronic contributions without vacuum ρ 0 is measured in the invariant-mass range 0.15 < m ee < 0.7 GeV / c 2 , where an excess of dielectrons is observed in other experiments, and its value is 1.40 ± 0.28 ( stat . ) ± 0.08 ( syst . ) ± 0.27 ( cocktail ) . The dielectron spectrum measured in the invariant mass range 0 < m ee < 1 GeV / c 2 is consistent with …