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HYDRA-TPC Prototype - a Time Projection Chamber for Light Hypernuclei Study at R3B, GSI/FAIR
No full textHypernuclei offer a unique approach to investigating hyperon-nucleon interactions. However, their extremely short lifetimes, on the order of sub-nanoseconds, pose significant experimental challenges. The HYpernuclei Decay at R³B Apparatus (HYDRA) experiment, designed for operation within the R³B setup at GSI/FAIR, aims to perform heavy-ion collision experiments with the primary objective of performing high-precision invariant mass spectroscopy of light hypernuclei.This thesis presents the development of the HYDRA Time Projection Chamber (TPC) specifically designed for tracking π − produced from hypernuclear decays within the GLAD magnet of the R³B. The TPC incorporates a double-layer wired drift field cage with a drift distance of 300 mm and an active area of 256 × 88 mm2. A hybrid amplification stage was implemented, comprising a Gas Electron Multiplier (GEM) and a Micromegas detector. This configuration is expected to achieve an ion back-flow of less than 1%.The design of the field cage was optimized through two-dimensional simulations employing the finite element method and Monte Carlo techniques to ensure a homogeneous drift field. Electron drift displacement was determined to be less than 250 µm at the edge of the active region and less than 200 µm in the central regionof the TPC.The gain performance of the TPC was characterized using an X-ray source. By adjusting the high voltage applied to the electrodes, the influence of varying high voltages in different regions on the overall effective gain of the TPC was quantified.The TPC was successfully commissioned with a front-end readout system incorporating multiplexing boards and digitizing readout electronics based on the GET system. Subsequently, its tracking performance was assessed through measurements of laser tracks generated by a 266-nm ultraviolet laser source and reflected into the drift volume by micromirror bundles, which were integrated within the TPC. A tracking algorithm was developed to reconstruct these laser tracks. Experimental results demonstrated a spatial resolution better than 3 mm in the drift direction, while the pad plane resolution did not meet the desired 200 µm requirement.Finally, the influence of magnetic fields on the drift electron trajectories was investigated within the GLAD magnet at magnetic field strengths ranging from 0 to 0.92 T
AsyEOS Software
No full textThe AsyEOS (Asymmetric-matter Equation-Of-State) directory within the R3BRoot framework provides the full detector definitions, Monte Carlo simulation tools, and digitization algorithms for the detectors used in the AsyEOS/R3B (Reactions with Relativistic Radioactive Beams) experimental campaign at the GSI/FAIR (Facility for Antiproton and Ion Research) facility. AsyEOS-R3BRoot, developed on top of the FairRoot framework, is a versatile toolkit for performing Monte Carlo simulations and processing experimental data to measure the flows of neutrons and light charged particles produced in Nucleus-Nucleus collisions in order to investigate symmetry energy of the nuclear equation of state at densities above the saturation one. The AsyEOS software package is a source distribution with recurring releases for macOS and Linux
Search for charmoniumlike hybrid via at center-of-mass energies between 4.258 and 4.681 GeV
No full textProbing Strangeness Hadronization with Event-by-Event Production of Multistrange Hadrons
No full textThis Letter presents the first measurement of event-by-event fluctuations of the net number (difference between the particle and antiparticle multiplicities) of multistrange hadrons Ξ- and Ξ¯+ and its correlation with the net-kaon number using the data collected by the ALICE Collaboration in pp, p-Pb, and Pb-Pb collisions at a center-of-mass energy per nucleon pair = 5.02 TeV. The statistical hadronization model with a correlation over three units of rapidity between hadrons having the same and opposite strangeness content successfully describes the results. On the other hand, string-fragmentation models that mainly correlate strange hadrons with opposite strange quark content over a small rapidity range fail to describe the data
PEEK-Polymer as a vacuum-window in high power rf-couplers
No full textPEEK is an advanced polymer known for its exceptional mechanical strength, thermal stability, and radiation resistance, making it a promising candidate for applications in extreme environments. This study explores the viability of PEEK as a vacuum window material in high-power radio frequency (RF) couplers. Traditionally, materials such as ceramics are employed for this purpose; however, they are costly to manufacture and impose limitations during the design process. PEEK offers additional advantages, including the possibility of additive manufacturing, which enables the integration of cooling channels for efficient thermal management. The research evaluates PEEK's electrical, thermal, and mechanical properties under conditions typical of high-power RF couplers, such as vacuum stability, RF-induced heating, and electromagnetic transparency. At the Institute for Applied Physics (IAP), PEEK is tested as a vacuum window material in high-power experiments up to 35 kW. Following these tests, the material is analyzed to assess its performance and suitability for RF applications
Physics of the gluon mass gap
No full textIt has long been known that the gluon propagator in Landau-gauge QCD exhibits a mass gap; and its emergence has been ascribed to the action of the Schwinger mechanism in the gauge sector of QCD. In the present work, we relate this property to the physical mass gap of QCD by considering two observables associated with confinement and chiral symmetry breaking, namely the confinement-deconfinement transition temperature and the pion decay constant, respectively. It turns out that the first observable is linearly proportional to the gluon mass gap, a fact that allows us to assign a direct physical meaning to this scale. Moreover, we identify three distinct momentum regimes in the gluon propagator, ultraviolet, intermediate, and deep infrared, and assess their impact on the aforementioned observables. Both observables are sensitive to the first two regions of momenta, where functional approaches essentially coincide, but are insensitive to the third, deep infrared, regime. The combined information is used for a simple fit for the gluon propagator, all of whose parameters admit a clear physical interpretation. Finally, we discuss how this fit can help us access the intertwined dynamics of confinement and chiral symmetry breaking in QCD-type theories
