Produkce neutrálníh mezonů ve srážkách Ag+Ag při energii 1.58 A GeV s využitím elektromagnetického kalorimetru HADESu

Title: Neutral Meson Production in Ag+Ag Collisions at 1.58 A GeV with HADES Electromagnetic Calorimeter Author: Alexandr Prozorov Abstract: The Dielectron Spectrometer HADES operating at the SIS18 synchro- tron, FAIR/GSI Darmstadt, recently provided new intriguing results on the pro- duction of electron pairs and strangeness from nucleus-nucleus collisions, as well as from elementary reactions, in the energy region of 1 − 2 A GeV. In 2019 the spectrometer was complemented by an electromagnetic calorimeter based on lead- glass modules, which allows us to measure photons and thus study the production of π0 and η mesons via their two-photon decay. Knowledge of the neutral-meson production is a mandatory prerequisite for the interpretation of dielectron data. In particular, the directed and elliptic flow of neutral mesons with respect to transverse momentum and rapidity will be shown for different centrality classes in Ag + Ag collisions at 1.58 A GeV. The results of the analysis corresponding to the 14 × 109 events will be confronted with the results of other experiments and with the current model calculations. Keywords: baryonic medium, hadrons, relativistic heavy-ion collisions, neutral mesons, pion flowNázev práce: Produkce neutrálníh mezonů ve srážkách Ag+Ag při energii 1.58 A GeV s využitím elektromagnetického kalorimetru HADESu Autor: Alexandr Prozorov Abstrakt: Dielektronový spektrometr HADES, provozovaný na synchrotronu SIS18 v Darmstadtu v laboratoři FAIR/GSI, nedávno poskytl nové zajímavé vý- sledky týkající se produkce elektronových párů a podivnosti ve srážkách jádra s jádrem a v elementárních reakcích v oblasti energie 1 − 2 A GeV. V roce 2019 byl spektrometr doplněn elektromagnetickým kalorimetrem založeným na modu- lech s olovnatého skla, který nám umožnil měřit fotony a tak studovat produkci mezonů π0 a η prostřednictvím jejich rozpadu na dva fotony. Znalost produkce ne- utrálních mezonů je nutným předpokladem pro interpretaci dat o dielektronech. Konkrétně budou ukázány výtěžky, přímý a eliptický tok neutrálních mezonů vzhledem k příčné hybnosti a rapiditě pro různé centrality ve srážkách Ag + Ag při 1,58 A GeV. Výsledky analýzy odpovídajících 14 × 109 událostí budou kon- frontovány s výsledky jiných experimentů a s aktuálními modelovými výpočty. Klíčová slova: Baryonové medium, hadrony, Srážky těžkých iontů, neutrální me- zony, tok pionůFaculty of Mathematics and PhysicsMatematicko-fyzikální fakult

Monocular visual odometry and 3D reconstruction

This article concerns the algorithms of stereovision and visual odometry, which can be applied to solve a three-dimensional reconstruction problem through monocular vision and describes the basic stages of the system, advantages and disadvantages of the above-mentioned methods

Neutral meson production in Ag+Ag at √SNN = 2.55 GeV

Abstract. Relativistic nucleus-nucleus collisions offer a unique possibility for studying nuclear matter under the influence of high temperature and pressure. During the collision a system of interacting nucleons, resonances, and mesons, called hadronic fireball, is created. HADES is a unique experiment capable of simultaneously measuring all three species of pions for this energy regime. Results on neutral pion production in Ag + Ag collisions at √SNN = 2.55 GeV (beam energy 1.58 A GeV) with 14 billion collected events will be presented. A measurement of a directed and elliptic flow, and yields of neutral pions corrected for detector acceptance and efficiency will be shown with respect to transverse momentum and rapidity for certain centrality classes; and further compared with the data, and charged pion data measured in the same experiment. In addition, the obtained results will be confronted with up-to-date model calculations

Neutral Meson Production in Ag+Ag Collisions at 1.58 A GeV with HADES Electromagnetic Calorimeter

Title: Neutral Meson Production in Ag+Ag Collisions at 1.58 A GeV with HADES Electromagnetic Calorimeter Author: Alexandr Prozorov Abstract: The Dielectron Spectrometer HADES operating at the SIS18 synchro- tron, FAIR/GSI Darmstadt, recently provided new intriguing results on the pro- duction of electron pairs and strangeness from nucleus-nucleus collisions, as well as from elementary reactions, in the energy region of 1 − 2 A GeV. In 2019 the spectrometer was complemented by an electromagnetic calorimeter based on lead- glass modules, which allows us to measure photons and thus study the production of π0 and η mesons via their two-photon decay. Knowledge of the neutral-meson production is a mandatory prerequisite for the interpretation of dielectron data. In particular, the directed and elliptic flow of neutral mesons with respect to transverse momentum and rapidity will be shown for different centrality classes in Ag + Ag collisions at 1.58 A GeV. The results of the analysis corresponding to the 14 × 109 events will be confronted with the results of other experiments and with the current model calculations. Keywords: baryonic medium, hadrons, relativistic heavy-ion collisions, neutral mesons, pion flo

Neutral Meson Production in Ag+Ag Collisions at 1.58 A GeV with HADES Electromagnetic Calorimeter

Title: Neutral Meson Production in Ag+Ag Collisions at 1.58 A GeV with HADES Electromagnetic Calorimeter Author: Alexandr Prozorov Abstract: The Dielectron Spectrometer HADES operating at the SIS18 synchrotron, FAIR/GSI Darmstadt, recently provided new intriguing results on the pro- duction of electron pairs and strangeness from nucleus-nucleus collisions, as well as from elementary reactions, in the energy region of 1 − 2 A GeV. In 2019 the spectrometer was complemented by an electromagnetic calorimeter based on lead- glass modules, which allows us to measure photons and thus study the production of π0 and η mesons via their two-photon decay. Knowledge of the neutral-meson production is a mandatory prerequisite for the interpretation of dielectron data. In particular, the directed and elliptic flow of neutral mesons with respect to transverse momentum and rapidity will be shown for different centrality classes in Ag + Ag collisions at 1.58 A GeV. The results of the analysis corresponding to the 14 × 109 events will be confronted with the results of other experiments and with the current model calculations. Keywords: baryonic medium, hadrons, relativistic heavy-ion collisions, neutral mesons, pion flo

Methods of complete surface reconstruction through merging of point clouds according to stereo vision data

This article concerns the stack of algorithms which can be applied to the task of 3d reconstruction using stereo vision techniques. Stereo vision data represented as a set of single-valued surfaces of the point clouds that have overlaping areas. They may differ in density and regularity, but the whole reconstructed object model consists of a subset of single-valued surfaces. Thus, the task is to find a method of transformation of these original surfaces by minimizing some functional chracterizing the degree of matching. Considered the methods of representation of the point cloud as two-dimensional discrete functions, suggested variants of the measure of differences between source datasets, as well as methods of mutual localization of surfaces

An Algorithm for Quality Assessment of Images with Contrast Changes and Mean Shifts

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Exploring time like tranistions in pp, πp and AA reactions with HADES

Radiative transition of an excited baryon to a nucleon with emission of a virtual massive photon converting to dielectron pair (Dalitz decays) provides important information about baryon-photon coupling at low q2 in timelike region. A prominent enhancement in the respective electromagnetic transition Form Factors (etFF) at q2 near vector mesons ρ/ω poles has been predicted by various calculations reflecting strong baryon-vector meson couplings. The understanding of these couplings is also of primary importance for the interpretation of the emissivity of QCD matter studied in heavy ion collisions via dilepton emission. Dedicated measurements of baryon Dalitz decays in proton-proton and pion-proton scattering with HADES detector at GSI/FAIR are presented and discussed. The relevance of these studies for the interpretation of results obtained from heavy ion reactions is elucidated on the example of the HADES results

New results on light nuclei, hyperons and hypernuclei from HADES (HADES collaboration)

International audienceIn March 2019 the HADES experiment recorded 14 billion Ag+Ag collisions at √sNN = 2.55 GeV as a part of the FAIR phase-0 physics program. In this contribution, we present and investigate our capabilities to reconstruct and analyze weakly decaying strange hadrons and hypernuclei emerging from these collisions. The focus is put on measuring the mean lifetimes of these particles