CMS physics technical design report : Addendum on high density QCD with heavy ions

Peer reviewe

3D-CFD investigation into free convection flow above a heated horizontal cylinder: Comparisons with experimental data

A 3-D computational fluid dynamics (CFD) model is proposed for the first time to predict the existing particle -image velocimetry (PIV) data and measured Nusselt numbers collected from the liquid flow above a heated horizontal cylinder. The simulation results are obtained in the free convective water flow around a heated horizontal cylinder with the top surface open to air in the Rayleigh number range from 10(5) to 5 x 10(6) and a Prandtl number of 5.98. The submersion depth of the cylinder top below the free water surface is normalized by the cylinder diameter at H/D = 6. Excellent agreements between the computed and measured similarity solutions for a Rayleigh number of 1.33 x 10(6) prove the capability of the computational model to simulate flow velocity, boundary layers and Nusselt numbers present in a vertical plane perpendicular to the cylinder axis at different circumferential locations. The computational results concerning the periodic swaying motion of the plume and its time of a sway period are found to be consistent with the experimental observations. Additionally, the computational analysis reveals the correlation among the near-cylinder flow features, boundary-layer thickness and plume formation region. We further analyze the correspondence between the swaying motion in a plane perpendicular to the cylinder axis and meandering structure coupled with U-shaped velocity profiles in the axial direction. Furthermore, the effect of Rayleigh number on the velocity fields and heat transfer characteristics has been identified. In the frequency spectrum analysis of the Nusselt number fluctuations, we have found the correlation between the oscillation frequency of the plume swaying and heat transfer characteristics. (C) 2017 Elsevier Ltd. All rights reserved

CMS Physics Technical Design Report: Addendum on High Density QCD with Heavy Ions

This report presents the capabilities of the CMS experiment to explore the rich heavy-ion physics programme offered by the CERN Large Hadron Collider (LHC). The collisions of lead nuclei at energies $\sqrt{s_{NN}}= 5.5\,{\rm TeV}$ , will probe quark and gluon matter at unprecedented values of energy density. The prime goal of this research is to study the fundamental theory of the strong interaction \u2014 Quantum Chromodynamics (QCD) \u2014 in extreme conditions of temperature, density and parton momentum fraction (low- x ). This report covers in detail the potential of CMS to carry out a series of representative Pb-Pb measurements. These include "bulk" observables, (charged hadron multiplicity, low p T inclusive hadron identified spectra and elliptic flow) which provide information on the collective properties of the system, as well as perturbative probes such as quarkonia, heavy-quarks, jets and high p T hadrons which yield "tomographic" information of the hottest and densest phases of the reaction

The very forward CASTOR calorimeter of the CMS experiment

International audienceThe physics motivation, detector design, triggers, calibration, alignment, simulation, and overall performance of the very forward CASTOR calorimeter of the CMS experiment are reviewed. The CASTOR Cherenkov sampling calorimeter is located very close to the LHC beam line, at a radial distance of about 1 cm from the beam pipe, and at 14.4 m from the CMS interaction point, covering the pseudorapidity range of $-$6.6 $\lt\eta\lt$ $-$5.2. It was designed to withstand high ambient radiation and strong magnetic fields. The performance of the detector in measurements of forward energy density, jets, and processes characterized by rapidity gaps, is reviewed using data collected in proton and nuclear collisions at the LHC

The very forward CASTOR calorimeter of the CMS experiment

The physics motivation, detector design, triggers, calibration, alignment, simulation, and overall performance of the very forward CASTOR calorimeter of the CMS experiment are reviewed. The CASTOR Cherenkov sampling calorimeter is located very close to the LHC beam line, at a radial distance of about 1cm from the beam pipe, and at 14.4m from the CMS interaction point, covering the pseudorapidity range of −6.6 < η < −5.2. It was designed to withstand high ambient radiation and strong magnetic fields. The performance of the detector in measurements of forward energy density, jets, and processes characterized by rapidity gaps, is reviewed using data collected in proton and nuclear collisions at the LHC

CMS physics technical design report: Addendum on high density QCD with heavy ions

This report presents the capabilities of the CMS experiment to explore the rich heavy-ion physics programme offered by the CERN Large Hadron Collider (LHC). The collisions of lead nuclei at energies ,will probe quark and gluon matter at unprecedented values of energy density. The prime goal of this research is to study the fundamental theory of the strong interaction - Quantum Chromodynamics (QCD) - in extreme conditions of temperature, density and parton momentum fraction (low-x). This report covers in detail the potential of CMS to carry out a series of representative Pb-Pb measurements. These include "bulk" observables, (charged hadron multiplicity, low pT inclusive hadron identified spectra and elliptic flow) which provide information on the collective properties of the system, as well as perturbative probes such as quarkonia, heavy-quarks, jets and high pT hadrons which yield "tomographic" information of the hottest and densest phases of the reaction.0info:eu-repo/semantics/publishe