3,745 research outputs found
A new and finite family of solutions of hydrodynamics: Part II: Advanced estimate of initial energy densities
We derive a new, exact formula for the estimate of the initial energy
densities from a new family of finite and exact solution of relativistic
perfect fluid hydrodynamics. The new formula depends non-trivially on the speed
of sound and on the shape or width parameter of the measured (pseudo)rapidity
distribution.Comment: Invited talk of G. Kasza at the WPCF 2018 conference in Cracow,
Poland, May 22-26, 2018. Submitted to Acta Physica Polonica
A new and finite family of solutions of hydrodynamics: Part III: Advanced estimate of the life-time parameter
We derive a new formula for the longitudinal HBT-radius of the two particle
Bose-Einstein correlation function from a new family of finite and exact,
accelerating solution of relativistic perfect fluid hydrodynamics for a
temperature independent speed of sound. The new result generalizes the
Makhlin-Sinyukov and Herrmann-Bertsch formulae and leads to an advanced
life-time estimate of high energy heavy ion and proton-proton collisions
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
Estimation of safe chatter-free technological parameter regions for machining operations
AbstractExperimental cutting tests often show different dynamic behavior from the one predicted by means of theoretical mechanical models. One reason behind this observation is that stability lobe diagrams determined by standard linear stability analysis often under- or overestimate the region of chatter-free parameters. Therefore, reliable selection of technological parameters associated with optimal material removal rate is difficult in practice. In this paper, a simple formula is given to estimate the safe parameter region, where the machining operation is globally stable even for large disturbances. The analytical results are confirmed by numerical simulations
Mass hierarchy and energy scaling of the Tsallis--Pareto parameters in hadron productions at RHIC and LHC energies
The latest, high-accuracy identified hadron spectra measurements in
high-energy nuclear collisions led us to the investigation of the strongly
interacting particles and collective effects in small systems. Since
microscopical processes result in a statistical Tsallis-Pareto distribution,
the fit parameters and are well suited for identifying system size
scalings and initial conditions. Moreover, parameter values provide information
on the deviation from the extensive, Boltzmann-Gibbs statistics in
finite-volumes. We apply here the fit procedure developed in our earlier study
for proton-proton collisions. The observed mass and energy trends in
the hadron production are compared to RHIC dAu and LHC pPb data in different
centrality/multiplicity classes. Here we present new results on mass hierarchy
in pp and pA from light to heavy hadrons.Comment: Talk given by G.B\'ir\'o at SQM 2017, Utrecht, 4 page
MWP-fit: a program for multiple whole-profile fitting of diffraction peak profiles by ab initio theoretical functions
A computer program has been developed for the determination of micro-structural parameters from diffraction profiles of materials with cubic or hexagonal crystal lattices. The measured profiles or their Fourier transforms are fitted by ab initio theoretical functions for size and strain broadening. In the calculation of the theoretical functions, it is assumed that the crystallites have log-normal size distribution and that the strain is caused by dislocations. Strain and size anisotropy are taken into account by the dislocation contrast factors and the ellipticity of the crystallites. The fitting procedure provides the median and the variance of the size distribution and the ellipticity of the crystallites, and the density and arrangement of the dislocations. The efficiency of the program is illustrated by examples of severely deformed copper and ball-milled lead sulfide specimens
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