717 research outputs found
Rapidity-dependence of jet shape broadening and quenching
The jet shape modification due to partonic energy loss in the dense QCD
matter is investigated by the help of the special transverse energy-energy
correlator in the vicinity of maximum energy deposition of every event. In the
accepted scenario with scattering of jet hard partons off comoving medium
constituents this correlator is independent of the pseudorapidity position of a
jet axis and becomes considerably broader (symmetrically over the
pseudorapidity and the azimuthal angle) in comparison with -collisions. At
scattering off "slow" medium constituents the broadening of correlation
functions is dependent on the pseudorapidity position of a jet axis and
increases noticeably in comparison with the previous scenario for jets with
large enough pseudorapidities. These two considered scenarios result also in
the different dependence of jet quenching on the pseudorapidity.Comment: 9 pages, 7 figures, 1 table, RevTex4, typos corrected, accepted for
publication in Phys. Rev.
The multiplicity and the spectra of secondaries correlated with the leading particle energy
The spectra of leading particles of different nature in pp-collisions at E sub 0 = 33 GeV are obtained. The multiplicities and the spectra of secondaries, mesons, gamma-quanta, lambda and lambda-hyperons and protons for different leading particle energy ranges are determined
Modular detector for deep underwater registration of muons and muon groups
Registration and identification of muons and muon groups penetrating into the ocean depth, can be performed using a modular multilayer detector with high resolution bidimensional readout - deep underwater calorimeter (project NADIR). Laboratory testing of a prototype sensor cell with liquid scintillator in light-tight casing, testifies to the practicability of the full-scale experiment within reasonable expences
The system of EAS time analysis
The extensive air showers' (EAS) front shape, angle of incidence, disk thickness, particle distribution along the shower, on the delayed and EAS front advancing particles were determined. The suggested system of the EAS time analysis allows determination of the whole EAS longitudinal structure at the observation points. The information from the detectors is continuously recorded in the memory with the memory cell switching in 5 ns, this enables fixation of the moment of pulse input from the detector with an accuracy to + or - 2.5 ns. Along with the fast memory, a slow memory with the cell switching in 1 micron s is introduced in the system, this permits observation of relatively large time intervals with respect to the trigger pulse with an appropriately lower accuracy
Medium-modified fragmentation of b-jets tagged by a leading muon in ultrarelativistic heavy ion collisions
The possibility to observe the medium-modified fragmentation of hard b-quarks
tagged by a leading muon in ultrarelativistic heavy ion collisions is analyzed.
We have found that reasonable statistics, ~20000 events per 1 month of LHC run
with lead beams, can be expected for the realistic geometrical acceptance and
kinematic cuts. The numerical estimates on the effect of the medium-induced
softening b-jet fragmentation function are given.Comment: 12 pages in LaTeX (including 3 figures in EPS-format
Elliptic flow studies using the CMS detector
The azimuthal anisotropy of charged particles in heavy ion collisions is an important probe of quark-gluon plasma evolution at early stages. The nuclear reaction plane can be determined independently by different detector subsystems and using different analysis methods. This paper reports the capability of the CMS detector at the LHC to reconstruct the reaction plane of the collision and to me asure elliptic flow with calorimetry and a tracking system. The analysis is based on a full CMS detector simulation of \rm{Pb+Pb} events with the HYDJET event generator
Two-dimensional discrete wavelet analysis of multiparticle event topology in heavy ion collisions
The event-by-event analysis of multiparticle production in high energy hadron
and nuclei collisions can be performed using the discrete wavelet
transformation. The ring-like and jet-like structures in two-dimensional
angular histograms are well extracted by wavelet analysis. For the first time
the method is applied to the jet-like events with background simulated by event
generators, which are developed to describe nucleus-nucleus collisions at LHC
energies. The jet positions are located quite well by the discrete wavelet
transformation of angular particle distribution even in presence of strong
background.Comment: 6 pages, 6 figure
Azimuthal anisotropy of jet quenching at LHC
We analyze the azimuthal anisotropy of jet spectra due to energy loss of hard
partons in quark-gluon plasma, created initially in nuclear overlap zone in
collisions with non-zero impact parameter. The calculations are performed for
semi-central Pb-Pb collisions at LHC energy.Comment: Talk given at Fourth International Conference "Physics and
Astrophysics of Quark-Gluon Plasma", November 26-30, 2001; 4 pages including
4 eps-figure
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