The statistical hadronization model approach to sNN=200\sqrt{s_{NN}}=200 GeV Au-Au collisions: pTp_{T}-spectra fits and global variable predictions

Three possible scenarios of the statistical hadronization model are reexamined with the use of the $p_{T}$ spectra of the PHENIX and very low $p_{T}$ PHOBOS measurements at $\sqrt{s_{NN}}=200$ GeV. These scenarios are: (\textit{a}) full chemical non-equilibrium, (\textit{b}) strangeness chemical non-equilibrium and (\textit{c}) chemical equilibrium. Fits to the spectra are done within the Cracow single-freeze-out model, which takes into account both the expansion and resonance decays. Predictions for spectra of $\phi$, $K(892)^{\ast 0}$ and $\pi^{0}$ are also given. The global variables like the transverse energy at midrapidity, the charged particle multiplicity at midrapidity and the total multiplicity of charged particles are evaluated and their predicted values agree qualitatively well with the experimental data. The thorough analysis within this model suggests that the chemical full non-equilibrium case is the least likely and both other cases are of the similar likelihood. It is also shown that if the full chemical non-equilibrium freeze-out took place it could manifest itself in the enhancement of the $\pi^{0}$-production at very low transverse momenta.Comment: 19 pages, 16 figures (included). This is the final version accepted in Phys. Rev. C. Figs.9 and 10 have been changed since it turned out that the data on \phi meson production were corrected for the branching ratio of \phi decay into K_{+}K_{-

Properties of an equilibrium hadron gas subjected to the adiabatic longitudinal expansion

We consider an ideal gas of massive hadrons in thermal and chemical equilibrium. The gas expands longitudinally in an adiabatic way. This evolution for a baryonless gas reduces to a hydrodynamic expansion. Cooling process is parametrized by the sound velocity. The sound velocity is temperature dependent and is strongly influenced by hadron mass spectrum.Comment: 7pages, 7 figures-- uucoded file of figures appended at the end, separated from the paper by lines with many dashe

Centrality dependence of global variables in relativistic heavy ion collisions: Final pTp_{T} data analysis in the framework of a statistical model

The global variables like the transverse energy at midrapidity, the charged particle multiplicity at midrapidity and the total multiplicity of charged particles are evaluated in the single-freeze-out statistical model for different centrality bins at RHIC at $\sqrt{s_{NN}}=130$ and 200 GeV. Full description of decays of hadron resonances is applied in these estimations. The geometric parameters of the model are obtained from the fit to the final data on the $p_{T}$ spectra. The predicted values of the global variables agree qualitatively well with the experimental data. The centrality independence of the total number of charged particles per participant pair has been also reproduced.Comment: Revtex, 12 figures (included), 16 pages. This is the revised final version accepted for publication in Physical Review C. The main difference with the first version is that the geometric parameters of the model have been fitted again with the use of the newer estimates of the statistical parameters reported in Refs. [20,21] for the case of $\sqrt{s_{NN}}=200$ GeV. Also because of the editorial reasons the title has been slightly change

Transverse Energy per Charged Particle and Freeze-Out Criteria in Heavy-Ion Collisions

In relativistic nucleus-nucleus collisions the transverse energy per charged particle, E_T/N_ch, increases rapidly with beam energy and remains approximately constant at about 800 MeV for beam energies from SPS to RHIC. It is shown that the hadron resonance gas model describes the energy dependence, as well as the lack of centrality dependence, qualitatively. The values of E_T/N_ch are related to the chemical freeze-out criterium E/N about 1 GeV valid for primordial hadrons.Comment: 8 pages, 5 figure

SO(2)-Equivariant Downwash Models for Close Proximity Flight

Multirotors flying in close proximity induce aerodynamic wake effects on each other through propeller downwash. Conventional methods have fallen short of providing adequate 3D force-based models that can be incorporated into robust control paradigms for deploying dense formations. Thus, learning a model for these downwash patterns presents an attractive solution. In this paper, we present a novel learning-based approach for modelling the downwash forces that exploits the latent geometries (i.e. symmetries) present in the problem. We demonstrate that when trained with only 5 minutes of real-world flight data, our geometry-aware model outperforms state-of-the-art baseline models trained with more than 15 minutes of data. In dense real-world flights with two vehicles, deploying our model online improves 3D trajectory tracking by nearly 36% on average (and vertical tracking by 56%)

J/Psi suppression in colliding nuclei: statistical model analysis

We consider the $J/\Psi$ suppression at a high energy heavy ion collision. An ideal gas of massive hadrons in thermal and chemical equilibrium is formed in the central region. The finite-size gas expands longitudinally in accordance with Bjorken law. The transverse expansion in a form of the rarefaction wave is taken into account. We show that $J/\Psi$ suppression in such an environment, when combined with the disintegration in nuclear matter, gives correct evaluation of NA38 and NA50 data in a broad range of initial energy densities.Comment: 14 pages, 13 figures. Accepted for publication in Phys. Rev.

WDHA syndrome caused by pheochromocytoma: report of a case.

A case in which a pheochromocytoma secreted vasoactive intestinal peptide, causing WDHA syndrome, is reported. The patient, a 43-year-old woman, was seen because of intractable watery diarrhea, hypokalemia and weight loss. She was found to have a mass in the right adrenal area. Preoperatively, vasoactive intestinal peptide levels were elevated, and the diagnosis of WDHA syndrome was entertained. Exploratory laparotomy revealed a tumor of the right adrenal gland, measuring 15 x 15 cm, which was resected. Histologic examination revealed it to be a pheochromocytoma. Postoperatively, vasoactive intestinal peptide returned to normal. The patient had complete remission of symptoms, and has remained well since

Quark exchange model for charmonium dissociation in hot hadronic matter

A diagrammatic approach to quark exchange processes in meson-meson scattering is applied to the case of inelastic reactions of the type (Q\barQ)+(q\barq)\rightarrow (Q\barq) + (q\barQ), where $Q$ and $q$ refer to heavy and light quarks, respectively. This string-flip process is discussed as a microscopic mechanism for charmonium dissociation (absorption) in hadronic matter. The cross section for the reaction $J/\psi + \pi \to D+ \bar D$ is calculated using a potential model, which is fitted to the meson mass spectrum. The temperature dependence of the relaxation time for the \J/Psi distribution in a homogeneous thermal pion gas is obtained. The use of charmonium for the diagnostics of the state of hot hadronic matter produced in ultrarelativistic nucleus-nucleus collisions is discussed.Comment: 24 pages, 3 tables, 7 figure