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 $v_2(\eta)$, as determined recently by the PHOBOS experiment for Au+Au collisions at $\sqrt{s_{NN}} = 130$ and 200 GeV. With the same set of parameters, the Buda-Lund model describes also the transverse momentum dependence of $v_2$ 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

Model independent shape analysis of correlations in 1, 2 or 3 dimensions

A generic, model-independent method for the analysis of the two-particle short-range correlations is presented, that can be utilized to describe e.g. Bose-Einstein (HBT or GGLP), statistical, dynamical or other short-range correlation functions. The method is based on a data-motivated choice for the zero-th order approximation for the shape of the correlation function, and on a systematic determination of the correction terms with the help of complete orthonormal set of functions. The Edgeworth expansion is obtained for approximately Gaussian, the Laguerre expansion for approximately exponential correlation functions. Multi-dimensional expansions are also introduced and discussed.Comment: Latex, 15 pages, uses epsfig.sty elsart.sty, misprints correcte

Bose-Einstein correlations for Levy stable source distributions

The peak of the two-particle Bose-Einstein correlation functions has a very interesting structure. It is often believed to have a multivariate Gaussian form. We show here that for the class of stable distributions, characterized by the index of stability $0 < \alpha \le 2$, the peak has a stretched exponential shape. The Gaussian form corresponds then to the special case of $\alpha = 2$. We give examples for the Bose-Einstein correlation functions for univariate as well as multivariate stable distributions, and check the model against two-particle correlation data.Comment: 30 pages, 1 figure, an important misprint in former eqs. (37-38) and other minor misprints are corrected, citations update

New analytic solutions of the non-relativistic hydrodynamical equations

New solutions are found for the non-relativistic hydrodynamical equations. These solutions describe expanding matter with a Gaussian density profile. In the simplest case, thermal equilibrium is maintained without any interaction, the energy is conserved, and the process is isentropic. More general solutions are also obtained that describe explosions driven by heat production, or contraction of the matter caused by energy loss.Comment: 6 pages, LaTeX. Submitted to Physics Letters B. Shortened from 9 pages, errors corrected in the "More general solutions" sectio

A CERN LHC nyaláb luminozitásának abszolút kalibrációja és a p+p szórás hatáskeresztmetszete a TOTEM kísérletben = Absolute calibration of LHC beam luminosity and determination of total proton - proton cross section in the TOTEM experiment

A kutatási támogatás segítségével két fiatal kutató tölthetett mintegy 1 éves szakmai gyakorlatot a CERN LHC TOTEM kísérleténél. Egy egyetemi hallgató pedig első konferencia kiadványát készíthette el a TOTEM kísérlet Roman Pot detektorainak nyaláb impedancia méréséről. Publikációs tevékenységük eredményes munkát takar, és nem tükrözi azokat a nehézségeket amellyel 2008 szeptemberében, az LHC gyorsító működésének leállása után kellett szembesülnünk, és amely helyzet várhatóan idén év végére normalizálódik az LHC újraindításakor. Az ütköző nyalábok hiánya miatt részben át kellett terveznünk a kutatásokat: azokat a feladatokat soroltuk előre, amelyek az új helyzetben a TOTEM számára a legfontosabbak voltak. Részt vettünk a TOTEM Roman Pot detektorok impedanciájának meghatározásában. Teszteltük a TOTEM Római Fazék detektorok hatékonyságát . A TOTEM Online Adatgyűjtő és monitorozó szoftverében új adatformátumot vezettünk be. A kísérlet kérésére bekapcsolódtunk a TOTEM Detektor Kontroll Rendszer (DCS) hardver kiépítésébe is. A tervben szereplő teljes hatáskeresztmetszet mérést, valamint az LHC nyaláb luminozitásának modell-független meghatározását üktözések híján, az LHC indulásának csúszása miatt nem tudtuk megvalósítani, ezekre várhatóan a 2009/2010-es akadémiai évben, az LHC újraindítása után fog majd sor kerülni, a publikációk az OTKA támogatásának feltüntetésével jelennek majd meg. | Two young postdocs received a practical training in high energy particle physics in the TOTEM experiment at CERN LHC on this grant. An MSc student completed her first scientific publication on TOTEM Roman Pot detectors. The publications of the participants report on successful research, and does not reflect the difficulties that arised soon after the start of the grant period due to the cessation of the operations of the CERN LHC accelerator in September 2008, a difficult situation that is expected to be normalized only by a successful restart of CERN LHC scheduled presently to the end of 2009. The lack of colliding beams in LHC resulted in a re-scheduling and re-planning of the proposed research: we had to give high priority to those topics that were most important for the TOTEM experiment in this situation. We participated in the beam impedance measurements of the TOTEM Roman Pot subdetectors. We introduced a new data format in the TOTEM online monitoring and data acquisition system. Upon the request of TOTEM we participated in the construction of hardware for the TOTEM Detector Control System. The planned measurement of total cross sections and the absolute calibration of the LHC beam luminosity was postponed due to lack of colliding proton beams and the cessation of LHC operations mentioned above. These measurements will take place after the successfull restart of LHC, expected in the 2009/10 academic year

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

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

Scaling properties of spectra in new exact solutions of rotating, multi-component fireball hydrodynamics

We describe fireballs that rehadronize from a perfect fluid of quark matter, characterized by the lattice QCD equation of state, to a chemically frozen, multi-component mixture, that contains various kinds of observable hadrons. For simplicity and clarity, we apply a non-relativistic approximation to describe the kinematics of this expansion. Unexpectedly, we identify a secondary explosion that may characterize fireball hydrodynamics at the QCD critical point. After rehadronization, the multi-component mixture of hadrons keeps on rotating and expanding together, similarly to a single component fluid. After kinetic freeze-out, the effective temperature $T_{i}$ of the single-particle spectra of hadron type $h_i$ is found to be a sum of the kinetic freeze-out temperature $T_f$ (that is independent of the hadron type $h_i$) and a term proportional to the mass $m_i$ of hadron type $h_i$. The coefficient of proportionality to $m_i$ is also found to be independent of the hadron type $h_i$ but be dependent on the radial flow and vorticity of collective dynamics.Comment: 12 pages, 2 figures, 6 tables, invited talk of G. Kasza at the 10th Bolyai-Gauss-Lobachevsky conference, Gy\"ongy\"os, Hungary, Aug. 21-25, 2017. Submitted for a publication to the MDPI journal Univers