685 research outputs found
Buda-Lund hydro model for ellipsoidally symmetric fireballs and the elliptic flow at RHIC
The ellipsoidally symmetric extension of Buda-Lund hydrodynamic model is
shown here to yield a natural description of the pseudorapidity dependence of
the elliptic flow , as determined recently by the PHOBOS experiment
for Au+Au collisions at and 200 GeV. With the same set of
parameters, the Buda-Lund model describes also the transverse momentum
dependence of of identified particles at mid-rapidity. The results
confirm the indication for quark deconfinement in Au+Au collisions at RHIC,
obtained from a successful Buda-Lund hydro model fit to the single particle
spectra and two-particle correlation data, as measured by the BRAHMS, PHOBOS,
PHENIX and STAR collaborations.Comment: 16 pages, 2 figures, 1 table added, discussion extended and an
important misprint in the caption of Fig. 1 is correcte
Simple analytic solution of fireball hydrodynamics
A new family of simple analytic solutions of hydrodynamics is found for
non-relativistic, rotationally symmetric fireballs assuming an ideal gas
equation of state. The solution features linear flow profile and a non-trivial
transverse temperature profile. The radial temperature gradient vanishes only
in the collisionless gas limit. The Zimanyi-Bondorf-Garpman solution and the
Buda-Lund parameterization of expanding hydrodynamical sources are recovered as
special cases. The results are applied to predict new features of proton-proton
correlations and spectra data at 1.93 AGeV Ni + Ni reactions.Comment: Latex, Revte
Weak convergence of Vervaat and Vervaat Error processes of long-range dependent sequences
Following Cs\"{o}rg\H{o}, Szyszkowicz and Wang (Ann. Statist. {\bf 34},
(2006), 1013--1044) we consider a long range dependent linear sequence. We
prove weak convergence of the uniform Vervaat and the uniform Vervaat error
processes, extending their results to distributions with unbounded support and
removing normality assumption
A new family of exact and rotating solutions of fireball hydrodynamics
A new class of analytic, exact, rotating, self-similar and surprisingly
simple solutions of non-relativistic hydrodynamics are presented for a
three-dimensionally expanding, spheroidally symmetric fireball. These results
generalize earlier, non-rotating solutions for ellipsoidally symmetric
fireballs with directional, three-dimensional Hubble flows. The solutions are
presented for a general class of equations of state that includes the lattice
QCD equations of state and may feature inhomogeneous temperature and
corresponding density profiles.Comment: Dedicated to T. Kodama on the occasion of his 70th birthday. 15
pages, no figures. Accepted for publication at Phys. Rev. C. Minor rewritings
from previous versio
Simple solutions of fireball hydrodynamics for rotating and expanding triaxial ellipsoids and final state observables
We present a class of analytic solutions of non-relativistic fireball
hydrodynamics for a fairly general class of equation of state. The presented
solution describes the expansion of a triaxial ellipsoid that rotates around
one of the principal axes. We calculate the hadronic final state observables
such as single-particle spectra, directed, elliptic and third flows, as well as
HBT correlations and corresponding radius parameters, utilizing simple analytic
formulas. We call attention to the fact that the final tilt angle of the
fireball, an important observable quantity, is not independent on the exact
definition of it: one gets different angles from the single-particle spectra
and from HBT measurements. Taken together, it is pointed out that these
observables may be sufficient for the determination of the magnitude of the
rotation of the fireball. We argue that observing this rotation and its
dependence on collision energy would reveal the softness of the equation of
state. Thus determining the rotation may be a powerful tool for the
experimental search for the critical point in the phase diagram of strongly
interacting matter.Comment: 17 pages, 12 figure panel
Excitation function of elastic scattering from a unitarily extended Bialas-Bzdak model
The Bialas-Bzdak model of elastic proton-proton scattering assumes a purely
imaginary forward scattering amplitude, which consequently vanishes at the
diffractive minima. We extended the model to arbitrarily large real parts in a
way that constraints from unitarity are satisfied. The resulting model is able
to describe elastic scattering not only at the lower ISR energies but also
at 7 TeV in a statistically acceptable manner, both in the
diffractive cone and in the region of the first diffractive minimum. The total
cross-section as well as the differential cross-section of elastic
proton-proton scattering is predicted for the future LHC energies of
8, 13, 14, 15 TeV and also to 28 TeV. A non-trivial, significantly
non-exponential feature of the differential cross-section of elastic
proton-proton scattering is analyzed and the excitation function of the
non-exponential behavior is predicted. The excitation function of the shadow
profiles is discussed and related to saturation at small impact parameters.Comment: Talk by T. Csorgo presented at the WPCF 2014 conference, Gyongyos,
Hungary, August 25-29 201
Simple solutions of fireball hydrodynamics for self-similar elliptic flows
Simple, self-similar, elliptic solutions of non-relativistic fireball
hydrodynamics are presented, generalizing earlier results for spherically
symmetric fireballs with Hubble flows and homogeneous temperature profiles. The
transition from one dimensional to three dimensional expansions is investigated
in an efficient manner.Comment: 12 pages, 4 figures in 8 .eps files, references to recent data added,
accepted in Physics Letters
Detailed description of accelerating, simple solutions of relativistic perfect fluid hydrodynamics
In this paper we describe in full details a new family of recently found
exact solutions of relativistic, perfect fluid dynamics. With an ansatz, which
generalizes the well-known Hwa-Bjorken solution, we obtain a wide class of new
exact, explicit and simple solutions, which have a remarkable advantage as
compared to presently known exact and explicit solutions: they do not lack
acceleration. They can be utilized for the description of the evolution of the
matter created in high energy heavy ion collisions. Because these solutions are
accelerating, they provide a more realistic picture than the well-known
Hwa-Bjorken solution, and give more insight into the dynamics of the matter. We
exploit this by giving an advanced simple estimation of the initial energy
density of the produced matter in high energy collisions, which takes
acceleration effects (i.e. the work done by the pressure and the modified
change of the volume elements) into account. We also give an advanced
estimation of the life-time of the reaction. Our new solutions can also be used
to test numerical hydrodynamical codes reliably. In the end, we also give an
exact, 1+1 dimensional, relativistic hydrodynamical solution, where the initial
pressure and velocity profile is arbitrary, and we show that this general
solution is stable for perturbations.Comment: 34 pages, 8 figures, detailed write-up of
http://arxiv.org/abs/nucl-th/0605070
Reduction principles for quantile and Bahadur-Kiefer processes of long-range dependent linear sequences
In this paper we consider quantile and Bahadur-Kiefer processes for long
range dependent linear sequences. These processes, unlike in previous studies,
are considered on the whole interval . As it is well-known, quantile
processes can have very erratic behavior on the tails. We overcome this problem
by considering these processes with appropriate weight functions. In this way
we conclude strong approximations that yield some remarkable phenomena that are
not shared with i.i.d. sequences, including weak convergence of the
Bahadur-Kiefer processes, a different pointwise behavior of the general and
uniform Bahadur-Kiefer processes, and a somewhat "strange" behavior of the
general quantile process.Comment: Preprint. The final version will appear in Probability Theory and
Related Field
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