580 research outputs found
On the Way to Future's High Energy Particle Physics Transport Code
High Energy Physics (HEP) needs a huge amount of computing resources. In
addition data acquisition, transfer, and analysis require a well developed
infrastructure too. In order to prove new physics disciplines it is required to
higher the luminosity of the accelerator facilities, which produce
more-and-more data in the experimental detectors. Both testing new theories and
detector R&D are based on complex simulations. Today have already reach that
level, the Monte Carlo detector simulation takes much more time than real data
collection. This is why speed up of the calculations and simulations became
important in the HEP community. The Geant Vector Prototype (GeantV) project
aims to optimize the most-used particle transport code applying parallel
computing and to exploit the capabilities of the modern CPU and GPU
architectures as well. With the maximized concurrency at multiple levels the
GeantV is intended to be the successor of the Geant4 particle transport code
that has been used since two decades successfully. Here we present our latest
result on the GeantV tests performances, comparing CPU/GPU based vectorized
GeantV geometrical code to the Geant4 version
A 'soft+hard' model for Pion, Kaon, and Proton Spectra and measured in PbPb Collisions at TeV
Hadron spectra measured in high-energy collisions present distributions which
can be derived from the non-extensive statistical and thermodynamical
phenomena. Based on earlier theoretical developments, it seems, the methods are
very applicable for jets hadronization processes in electron-positron,
proton-proton, and even in heavy-ion collisions.
Here, we present what can was learnt from the recent theoretical and
phenomenological developments: transverse momentum spectra and azimuthal
anisotropy () of charge averaged pions, kaons and protons stemming from
central Pb+Pb collisions at = 2.76 ATeV are described
\textit{analytically} in a `soft + hard' model.
In this model, we propose that hadron yields produced in heavy-ion collisions
are simply the sum of yields stemming from jets (hard yields) in addition to
the yields originating from the Quark-Gluon Plasma (soft yields). The hadron
spectra in both types of yields are approximated by the Tsallis--Pareto like
distribution
Non-extensive Motivated Parton Fragmentation Functions
A new form of fragmentation function is presented here, motivated by earlier
non-extensive studies of jet fragmentation. We parametrized our Tsallis-like
function on pion spectra and compared it to the most common fragmentation
function parametrizations. It is shown that the new form is in agreement with
earlier parametrizations, furthermore, its scale evolution overlap better with
the experimental data.Comment: 4 pages, 2 figures, Presented at Hot Quarks 2018. Submitted to MDPI
Proceeding
Multiplicity Dependence in the Non-Extensive Hadronization Model Calculated by the HIJING++ Framework
The non-extensive statistical description of the identified final state
particles measured in high energy collisions is well-known by its wide range of
applicability. However, there are many open questions that need to be answered,
including but not limited to, the question of the observed mass scaling of
massive hadrons or the size and multiplicity dependence of the model
parameters. This latter is especially relevant, since currently the amount of
available experimental data with high multiplicity at small systems is very
limited. This contribution has two main goals: On the one hand we provide a
status report of the ongoing tuning of the soon-to-be-released HIJING++ Monte
Carlo event generator. On the other hand, the role of multiplicity dependence
of the parameters in the non-extensive hadronization model is investigated with
HIJING++ calculations. We present cross-check comparisons of HIJING++ with
existing experimental data to verify its validity in our range of interest as
well as calculations at high-multiplicity regions where we have insufficient
experimental data.Comment: This paper is based on the talk at the 18th Zim\'anyi School,
Budapest, Hungary, 3-7 December 201
The effect of quantum fluctuations in compact star observables
Astrophysical measurements regarding compact stars are just ahead of a big
evolution jump, since the NICER experiment deployed on ISS on 14 June 2017.
This will soon provide data that would enable the determination of compact star
radius with less than 10% error. This poses new challenges for nuclear models
aiming to explain the structure of super dense nuclear matter found in neutron
stars.
Detailed studies of the QCD phase diagram shows the importance of bosonic
quantum fluctuations in the cold dense matter equation of state. Here, we using
a demonstrative model to show the effect of bosonic quantum fluctuations on
compact star observables such as mass, radius, and compactness. We have also
calculated the difference in the value of compressibility which is caused by
quantum fluctuations.
The above mentioned quantities are calculated in mean field, one-loop and in
high order many-loop approximation. The results show that the magnitude of
these effects is ~5%, which place it into the region where forthcoming
high-accuracy measurements may detect it.Comment: 6 pages 4 figues, minor corrections were adde
FRG Approach to Nuclear Matter at Extreme Conditions
Functional renormalization group (FRG) is an exact method for taking into
account the effect of quantum fluctuations in the effective action of the
system. The FRG method applied to effective theories of nuclear matter yields
equation of state which incorporates quantum fluctuations of the fields. Using
the local potential approximation (LPA) the equation of state for Walecka-type
models of nuclear matter under extreme conditions could be determined. These
models can be tested by solving the corresponding Tolman--Oppenheimer--Volkov
(TOV) equations and investigating the properties (mass and radius) of the
corresponding compact star models. Here, we present the first steps on this
way, we obtained a Maxwell construction within the FRG-based framework using a
Walecka-type Lagrangian.Comment: 6 pages, 3 figure
Multiplicity Dependence of the Jet Structures in pp Collisions at LHC Energies
We study the event multiplicity dependence of the jet structure in pp
collisions. We present evidence for jet shape modification due to multi-parton
interactions using PYTHIA and HIJING++ Monte Carlo (MC) event generators as an
input to our analysis. We introduce a characteristic jet size measure which is
independent of the choice of the simulation parameters, parton distribution
functions, jet reconstruction algorithms and even of the presence or absence of
multi-parton interactions. We also investigate heavy-flavor jets and show the
sensitivity of the multiplicity-differential jet structure to flavor-dependent
fragmentation.Comment: Presented at Hot Quarks 2018 -- Workshop for young scientists on the
physics of ultrarelativistic nucleus-nucleus collisions, Texel, The
Netherlands, September 7-14 2018. Submitted to MDPI Proceeding
Identified Two-particle Correlations and Quantum Number Conservations in p-p and Pb-Pb Collisions at LHC Energies
In this paper we continue the investigation of the effect of quantum number
conservations of pions, kaons, and protons, with very high transverse momenta
(up to 25 GeV/c), during parton fragmentation and hadronization in p-p and
Pb-Pb collisions at LHC energies. The strength of the conservation effects are
studied by identified two-particle correlations in Monte Carlo generated events
in the mid-rapidity region (). The simulated p-p events were
generated with PYTHIA 8, using its main default settings, at
~GeV, ~TeV, ~TeV, and
~TeV. In parallel to this, HIJING 1.36 was used to generate Pb-Pb
events at ~TeV with centralities ,
and . The extracted identified associated hadron spectra for charged
pion, kaon, and proton show identified trigger-hadron dependent splitting
between oppositely charged associated particle species in any nucleus-nucleus
collisions. The Pb-Pb data exhibits a peculiar splitting pattern as a function
of the transverse momentum of the associated particle both on the
near and away side that is different from the patterns observed in p-p
collisions. The splitting shows smooth evolution with collision energy and
event multiplicity in p-p collisions while in Pb-Pb collisions different trend
were observed for kaons and protons.Comment: 11 pages, 6 figures, Proceedings of the 10th International Workshop
on High-pT Physics in the RHIC/LHC era, 9-12 September 2014, SUBATECH Nante
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