The observed alignment of spots in the X-ray films in cosmic ray emulsion experiments is analyzed and interpreted in the framework of geometrical approach. It is shown that the high degree of ...alignment can appear partly due to the selection procedure of most energetic particles itself and the threshold on the energy deposition together with the transverse momentum conservation.
The method to simulate the rescattering and energy loss of hard partons in ultrarelativistic heavy ion collisions has been developed. The model is a fast Monte Carlo tool introduced to modify a ...standard PYTHIA jet event. The full heavy ion event is obtained as a superposition of a soft hydro-type state and hard multi-jets. The model is applied to the analysis of the jet quenching pattern at RHIC.
On jet structure in heavy ion collisions Lokhtin, I. P.; Alkin, A. A.; Snigirev, A. M.
The European physical journal. C, Particles and fields,
09/2015, Letnik:
75, Številka:
9
Journal Article
Recenzirano
Odprti dostop
The LHC data on jet fragmentation function and jet shapes in PbPb collisions at center-of-mass energy 2.76 TeV per nucleon pair are analyzed and interpreted in the frameworks of PYthia QUENched ...(PYQUEN) jet quenching model. A specific modification of longitudinal and radial jet profiles in most central PbPb collisions as compared with pp data is close to that obtained with PYQUEN simulations, taking into account wide-angle radiative and collisional partonic energy losses. The contribution of radiative and collisional loss to the medium-modified intra-jet structure is estimated.
The LHC data on azimuthal anisotropy harmonics from PbPb collisions at center-of-mass energy 2.76 TeV per nucleon pair are analyzed and interpreted in the framework of the HYDJET++ model. The ...cross-talk of elliptic
v
2
and triangular
v
3
flow in the model generates both even and odd harmonics of higher order. Comparison with the experimental data shows that this mechanism is able to reproduce the
p
T
and centrality dependencies of quadrangular flow
v
4
, and also the basic trends for pentagonal
v
5
and hexagonal
v
6
flows.
The important role of kinematic constraints for the origin of the alignment of hadron and photon families observed by the Pamir Collaboration in emulsion experiments with cosmic rays is discussed. ...Within the framework of the suggested approach, it is shown that the high degree of alignment of the interaction products of the target nuclei and cosmic rays can be a consequence of the selection procedure of the most energetic clusters of particles together with the law of conservation of transverse momentum. The results correctly describe the experimental data for three energetic centers and are also close enough to the measurements in the case of four and five clusters, which indicates encouraging prospects for the proposed method of explaining the alignment phenomenon.
Different mechanisms of
B
meson suppression in lead ion collisions at an energy of the Large Hadron Collider
= 5.02 TeV have been comparatively analyzed. It has been shown that the experimentally ...observed weak momentum dependence of the
B
meson suppression factor can be reproduced by the HYDJET++ model including the nuclear shadowing of initial parton distributions and radiative and collisional energy losses of heavy quarks in hot matter. A significant difference in the effects of the initial and final states on light and heavy hadron suppression has been revealed.
Jet quenching pattern at LHC in PYQUEN model Lokhtin, I. P.; Belyaev, A. V.; Snigirev, A. M.
The European physical journal. C, Particles and fields,
05/2011, Letnik:
71, Številka:
5
Journal Article
Recenzirano
Odprti dostop
The first LHC data on high transverse momentum hadron and dijet spectra in PbPb collisions at center-of-mass energy 2.76 TeV per nucleon pair are analyzed in the frameworks of PYQUEN jet quenching ...model. The presented studies for the nuclear modification factor of high-
p
T
hadrons and the imbalance in dijet transverse energy support the supposition that the intensive wide-angular (“out-of-cone”) medium-induced partonic energy loss is seen in central PbPb collisions at the LHC.
The LHC data on event-by-event harmonic flow coefficients measured in PbPb collisions at center-of-mass energy 2.76 TeV per nucleon pair are analyzed and interpreted within the HYDJET
+
+
model. To ...compare the model results with the experimental data the unfolding procedure is employed. The essentially dynamical origin of the flow fluctuations in hydro-inspired freeze-out approach has been established. It is shown that the simple modification of the model via introducing the distribution over spatial anisotropy parameters permits HYDJET
+
+
to reproduce both elliptic and triangular flow fluctuations and related to it eccentricity fluctuations of the initial state at the LHC energy.
The contributions of various effects to correlations of the average multiplicity of particles emitted in the forward hemisphere of heavy-ion collisions with the multiplicity of particles emitted in ...the backward hemisphere (forward–backward correlations) have been comparatively analyzed. It has been shown that the experimentally observed dependence of the strength of such correlations on the centrality of lead–lead ion collisions at the Large Hadron Collider energy
= 2.76 TeV can be reproduced by the HYDJET++ model if the hydrodynamic particle flow, decay of resonances, and production and suppression of high-energy quarks and gluons in hot matter are taken into account. The dominant mechanism of forward–backward correlations for the most central collisions involves the production and fragmentation of quark–gluon jets.
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