FAIR next generation scientists - 8th Edition Workshop

We theoretically investigate the angular distributions of fluorescence and photoelectrons emission based on density matrix formalism [1] in a pump-probe scheme dedicated for measuring the lifetime of odd singlet excited states of C III [2]. The energy levels, bound-bound and bound-free electric dipole matrix elements belonging to C III have been computed with the Dirac-Fock-Slater...

Electron-ion collision spectroscopy is a very successful approach for studying the properties of highly charged ions [1-3], in particular if low-energy dielectronic recombination (DR) resonances are scrutinized. The heavy-ion storage ring CRYRING@ESR of the international FAIR facility in Darmstadt,Germany, is particularly attractive for DR studies, since it is equipped with an electron cooler...

Gravitational-Wave and Kilonova measurements have established Binary Neutron Star (BNS) mergers as a predominant candidate for the production of the heaviest elements in our Universe. Under hot and dense conditions such as those encountered in BNS mergers, neutrino transport effects play a crucial role in initiating mass-outflows and in shaping the composition of the ejecta and of the...

We perform a systematic study of binary neutron star (BNS) mergers using relativistic hydrodynamical simulations with neutrinos by considering different total masses, mass ratios and different equations of state. By comparing asymmetric mergers to the corresponding symmetric mergers with the same total mass, we observe a systematic decrease in the dominant oscillation frequencies and an...

We computed three-dimensional radiative transfer calculations for the ejecta from a neutron star merger with line-by-line opacities for tens of millions of atomic transitions, composition from an r-process nuclear network, and time-dependent thermalization of decay products from individual 𝛼 and 𝛽− decay reactions. In contrast to expansion opacities and other wavelength-binned treatments, a...

The High Acceptance Di-Electron Spectrometer (HADES) at GSI, Darmstadt, Germany, is an experimental setup designed to investigate the hadronic matter in regions of large net baryon densities and moderate temperatures. It achieves this through fixed-target heavy-ion collisions with incident energies in the range of a few GeV/nucleon. This program is associated with proton and pion-induced...

The online data processing of the next generation of experiments conducted at FAIR requires a reliable reconstruction of event topologies and, therefore, will depend heavily on in-situ calibration procedures. In this study we present a neural network-based tool designed to provide real-time predictions of calibration constants, which rely on continuously available environmental data. To...

This talk will delve into the latest correlation and fluctuation measurements derived from the RHIC Beam Energy Scan-II (BES-II) data, collected by the STAR experiment. We will focus the recent results on higher-order net-proton cumulants ($C_{1}-C_{6}$) and transverse momentum correlations and fluctuations from BES-II data.

Specifically, for the higher order proton cumulants, we will...

The phase diagram of nuclear matter is one the most fundamental pieces of knowledge in modern physics, reflecting how QCD governs the thermodynamics of matter under extreme conditions. Not only related to the understanding of the early Universe, or used to describe the evolution of the system created in relativistic heavy-ion collisions, it has gained even more insights in the past years...

The High Acceptance Di-lepton Spectrometer (HADES) collaboration at GSI employs a pion beam to examine the characteristics of baryonic resonances and their decay channels. This pion-beam facility enables the generation of baryonic resonances at a fixed center of mass energy ($\sqrt{s}$), i.e. in the S-channel. Consequently, these beams possess a significant advantage over proton-induced...

In March 2024, the High Acceptance DiElectron Spectrometer (HADES) at GSI Darmstadt, Germany collected data on dielectron production in Au+Au collisions at a beam energy of 0.8 A GeV. One of the most intriguing aspects of this physics program is to investigate the strongly interacting medium which exhibits similar conditions to those in the final stages of a neutron-star merger or the early...

This work presents a preliminary analysis of the $Λ + 𝐾^{0}_{S} + 𝑝 + 𝜋^{+}$ final state in proton-proton scattering using data collected at T = 4.5 GeV with HADES at GSI in Darmstadt, Germany. The production of hyperons is of particular interest since it provides information about the role of N* resonances in strangeness production in NN interactions. Furthermore, this study could be relevant...

An experiment focused on hyperon production was carried out in 2022 with the upgraded HADES spectrometer. The upgrade includes a new Forward Detector system (FD) consisting of two PANDA-type Straw Tracking Stations, and an RPC. The measurements were performed with a T = 4.5 GeV proton beam impinging onto a LH$_{2}$ target.
Proton-proton elastic scattering events were selected based on...

Radiative transitions and decays of hadrons provide valuable information on their electromagnetic structure. The electromagnetic structure of the lowest lying excitation of the nucleon, the $\Delta$ resonance, remains of particular interest. This is accessible via radiative transitions such as $\Delta\rightarrow\Delta\gamma$ with real or, preferably, virtual photons . The first challenge is to...

In this contribution we present preliminary results on the dielectron production in p+p interactions at $1.58 \,$GeV beam energy measured with the High Acceptance DiElectron Spectrometer (HADES). The HADES RICH detector has been upgraded with a new photon detection camera which strongly enhances the electron...

Data analysis from subatomic physics experiments tends to be a complex endeavour, in particular due to the many systematic checks that this entails. A large number of parameters and combinations thereof must be considered, e.g. selection criteria, fitting ranges, bin sizes, background models, etc. As an aid in this endeavour, I have developed Sprout in parallel to my own data analysis within...

The CBM (Compressed Baryonic Matter) experiment to be built at the future FAIR facilities in Darmstadt, Germany aims to investigate the QCD phase diagram at high-net baryon densities and moderate temperatures. The FAIR accelerator will provide high-intensity heavy-ion beams for this fixed target experiment. To ensure the best operability of CBM at day one, a prototype of CBM is set up already...

The Compressed Baryonic Matter (CBM) experiment is one of the experimental pillars at the Facility for Antiproton and Ion Research (FAIR).
The Silicon Tracking System (STS) is the central detector for track reconstruction and momentum measurement. It is designed to measure heavy ion collisions at interaction rates up to 10 MHz. It comprises approximately 900 double-sided silicon strip...

The CBM experiment at FAIR-SIS100 will investigates strongly interacting matter at high baryon density and moderate temperature. One of proposed key observable is the measurement of the low mass vector mesons(LMVMs), which can be detected via their di-lepton decay channel. As the decayed leptons leave the dense and hot fireball without further interactions, they can provide unscathed...

The Compressed Baryonic Matter experiment is a future fixed target experiment designed to probe the QCD phase diagram at high baryonic density and moderate temperatures. Di-electrons are a penetrating probe well suited to understand the initial QCD medium since the electrons interact only electromagnetically and are hence not affected by the strong medium effects. Efficient identification of...

The hyperons are produced with a non-zero spin polarization that is
straight-forward to parameterize in processes involving virtual photons or
vector mesons, enable direct and precise CP violation tests. These CP tests
can be performed on e.g. $J/\psi,\psi' \to\Lambda\bar{\Lambda}$, $\Xi\bar{\Xi}$ and $\Sigma\bar{\Sigma}$. For the cascade hyperon decay the exclusive measurement of the final...

The QCD phase diagram has been actively studied over the years in the experimental, and theoretical domains using e.g. lattice QCD. The fluctuations of conserved charges like electric charge, baryon number, and strangeness are useful probes to study the QCD phase diagram. The experimental study of higher order cumulants provides insights into potential critical behaviour, and is being analysed...

The exact structure and inner workings of nucleons have been debated since the existence of quarks was first postulated. Since then, a large amount of experimental evidence has been gathered, indicating that nucleons and their excited states are not simple static quark states but are significantly influenced by the dynamics of baryon-meson interactions. In this context, it is interesting to...

The structure of $\Lambda(1405)$ resonance challenges hadron physicists for more than forty years. Its structure is controversially debated as either: an antikaon-nucleon bound state, a dynamically generated baryon resembling a meson-baryon molecule, or a resonance with $\pi\Sigma$ and $\bar{K}N$ poles. Experimental results vary in line shape and peak position, depending on reaction type,...

The main goal of the Compressed Baryonic Matter (CBM) Experiment at FAIR is to
probe the QCD phase diagram at high net-baryon densities and moderate temperatures with
nucleus-nucleus collisions, in order to locate the possible first order phase transition from
hadronic to partonic matter and its critical end point (CEP). The higher moments (cumulants)
of conserved quantities, such as...

The Silicon Tracking System (STS) in the upcoming heavy-ion CBM experiment is tailored for an unprecedented 10 MHz beam-target interaction rate. A unique integration strategy was employed to maintain a material budget within 2 - 8\% $X_0$ while ensuring ample granularity, spatial precision, and timing accuracy. The read-out electronics sit external to the sensitive volume, connected to...

The development of the Forward Spectator Detector (FSD) within
the CBM experiment represents a crucial step towards sucessful realization
of the CBM physics program - understanding of highly compressed
nuclear matter at the forthcoming FAIR facility. Specifically designed
for detection of collision participants at high collision rates at SIS-100 accelerator,
the FSD employs...

The Compressed Baryonic Matter experiment (CBM) at FAIR is designed to explore the QCD phase diagram at high net baryon densities and moderate temperatures by means of heavy ion collisions with energies from 2-11 AGeV beam energy (Au+Au collisions) and interaction rates up to 10 MHz, provided by the SIS100 accelerator. Leptons as penetrating probes not taking part in the strong interaction...

Under the extreme conditions of relativistic heavy-ion-collisions hypernuclei are created with large abundancies. Hypernuclei measurements provide insights into the equation-of-state of hadronic matter at high net-baryon densities, as well as into hyperon-nucleon and hyperon-hyperon-interactions. The Compressed Baryonic Matter (CBM) experiment at the future Facility for Anti-Proton and Ion...

To enhance the neutron detection capabilities of the CBM experiment, the use of existing calorimeter modules based on plastic scintillators with photomultiplier tubes (PMTs) has been proposed. These modules are designed to be placed behind the Forward Spectator Detector (FSD), with expected neutron detection efficiencies of approximately 30%. Each module has a hexagonal shape, with a length of...

Comprehension of the QCD phase diagram opens a window for a better understating of
matter dynamics inside massive objects like neutron stars. The Compressed Baryonic Matter experiment (CBM) at FAIR shall measure products coming out from ion collisions to study the equation-of-state of matter at high densities, to search phase transitions, chiral symmetry restoration, and exotic QCD matter....

The Compressed Baryonic Matter (CBM) experiment at the Facility for Antiproton and Ion Research (FAIR) in Darmstadt, Germany, aims to explore the QCD phase diagram at high baryon densities through high-energy nucleus-nucleus collisions and explore new states of matter. One of the crucial components of the CBM experiment is the Transition Radiation Detector (TRD), which is essential for...

$\beta$-decay rates are fundamental to understanding r-process nucleosynthesis, which is responsible for producing roughly half of the heavy elements. Existing theoretical global calculations of the rates use either Skyrme or relativistic quasiparticle random phase approximation (QRPA). These models yield very different predictions and are limited due to their treatment of nuclear many-body...

Recently, several works which focused on light isotopes and that were based on inclusive studies [1,2,3] have shown a reduction of the measured cross sections with respect to the theoretical predictions for nucleon-removal and single-nucleon knockout reactions. These studies have reached different conclusions regarding the dependence of the reduction factor observed of the spectroscopic factor...

In context of the search for the QCD critical endpoint in heavy-ion collisions, a deep understanding of the out-of-equilibrium dynamics of the system is necessary to make well-grounded predictions for signatures in final states. To this end, we investigate the dynamic critical behavior of a classical scalar field theory with symmetry in the dynamic universality class of Model A in two and...

The effective models of QCD are important tools for exploring the phase diagram of strongly interacting matter. They are particularly useful in the higher chemical potential regime, where the expected critical endpoint may be found, but which is inaccessible to lattice QCD due to the famous sign problem. These models are usually calculated in a mean-field approximation, which provides a...

Recently, the BESIII collaboration has produced new data for the $\Lambda$ baryon electric and magnetic form factor's ratio $G_E^\Lambda/G_M^\Lambda$ in the time-like region with high accuracy. By assuming the analyticity of the baryon form factors, a dispersive procedure can be used to analyze the data under a set of theoretical constraints. The dispersive procedure allows to determine...

The $\Psi(2S)$ is identified as the radial excitation of the $J/\Psi$. Based on perturbative QCD, the branching ratio of the $\Psi(2S)$ into some final hadron state should be approximately 12% of the branching ratio of the $J/\Psi$ to that same hadron final state. This is called the "12% rule". However, certain decay channels such as the $\rho \pi$ severely violate this 12% rule. Using the...