FAIR next generation scientists - 7th Edition Workshop

The storage of freshly produced radioactive particles in a storage ring is a straightforward way to achieve the most efficient use of such rare species as it allows for using the same rare ion multiple times. Employing storage rings for precision physics experiments with highly-charged ions (HCI) at the intersection of atomic, nuclear, plasma and astrophysics is a rapidly developing field of...

Spectroscopy of few electron highly-charged ions from medium to high atomic number Z allows to probe Quantum Electrodynamics (QED) effects in strong Coulomb fields. For such systems, theory can provide high-accuracy predictions, but experiments struggle to attain comparable precision. We present here two new measurements aimed at highest precision transition energy measurements in the X-ray...

Elastic scattering of hard x-rays on atoms is the fundamental photon-atom interaction process where both the incident and scattered photon carry the same energy. It is usually described as a coherent sum of different scattering processes depending on the scattering partner. Rayleigh scattering, being the 2nd order QED process of elastic scattering from bound electrons is the dominant...

Recent develpoments regarding metallic microcalorimeters (MMCs) have resulted in a new class of detectors for precision X-ray spectroscopy, for example the maXs detectors [1] (cryogenic micro-calorimeter arrays for high resolution X-ray spectroscopy), which have been developed within the SPARC collaboration. Outstanding features of MMCs are the combination of a very high energy resolution (1.7...

The study of x-ray emission associated with Radiative Recombination (RR) at “cold” temperature conditions, as it prevails at electron cooler devices at ion storage rings, allows for a stringent test of atomic structure and the subsequent x-ray emission characteristics. In particular, for heavy, highly charged ions at high-Z it enables to investigate in detail the prevailing cascade decay...

The detection of GW170817 and its electromagnetic counterpart AT2017gfo confirmed the expectation that a kilonova would accompany the merging of binary neutron stars, and subsequently there has been much interest in simulating kilonova emission to better understand the observations of AT2017gfo, including confirming that these are the primary production site of r-process material. The majority...

It has long since been established that observable actinides in the universe originate from the r-process. In 2017, the electromagnetic counterpart to the gravitational wave detection of two merging neutron stars was observed. From the light curve alone it was possible to characterize two ejecta components: one that contains low-Y𝑒 material such as lanthanides and possibly actinides, and a...

The kilonova AT 2017gfo that resulted from the merger of two neutron stars has provided new insights into the rapid neutron capture process that is responsible for producing many of the elements heavier than iron. As with supernovae, progress in understanding kilonova spectra can made both by using simple models to connect spectral features to particular elements, as well as by attempting to...

In recent years a lot of work has been dedicated to the analysis of multi-messenger signals from binary neutron star mergers. The electromagnetic signal, known as a kilonova, is powered by the radioactive decay of synthesized r-process nuclei and provides a unique opportunity to probe the in-situ operation of the r-process. Kilonova spectra are modeled with the aim of identifying spectral...

Recent measurements of gravitational waves and kilonova observations show that neutron star mergers are an important source of r-process elements. In fact, this astrophysical scenario is by now the first and only confirmed site of r-process element production. A reliable modelling of neutrino transport plays a key role in determining the ejecta composition and the resulting nucleosynthesis. In...

The mergers of neutron star binary systems are of great scientific interest as they can be used to explore and constrain the incompletely known Equation of State (EoS) at very high densities. Especially the formation of a black-hole due to a gravitational collapse is of interest. For a sufficiently high total binary mass the collapse occurs immediately after merging. This is called a prompt...

In this talk we focus on empirical relations between the gravitational wave frequencies produced by fluid oscillations in neutron stars and macroscopic characteristics like the radius and tidal deformability. Such relations can be employed to constrain the stellar properties, and in turn the underlying equation of state, from gravitational wave observations of neutron star systems. We focus on...

We investigate the final collapse of rotating and non-rotating pulsational pair-instability supernova progenitors with zero-age-main-sequence masses of 60, 80, and 115Msun and iron cores between 2.37Msun and 2.72Msun by 2D hydrodynamics simulations. Using the general relativistic NADA-FLD code with energy-dependent three-flavor neutrino transport by flux-limited diffusion allows us to follow...

We present a new analytic model describing gravitational wave emission in the post-merger phase of binary neutron star mergers. The model is described by a number of physical parameters that are related to various oscillation modes, quasi-linear combination tones or non-linear features that appear in the post-merger phase. The time evolution of the main post-merger frequency peak is taken into...

In this talk I will discuss how we can observe mergers of neutron stars with gravitational waves and how we can use them to extract information about neutron star macroscopic and microscopic properties.

A study of the composition and properties of neutron stars and proto-neutron stars is presented, based on a relativistic mean-field model. The baryonic matter equation of state (EoS) at zero and finite temperatures is computed within the FSU2H model, which has been updated according to the recent analysis on Xi baryon potential. The finite temperature EoS and composition of matter are computed...

In this talk I will present the recent progress in development of a thermodynamical model, which would be applicable for both astrophysics and heavy-ion collisions. To motivate this endeavor, the common aspects of both fields will be covered, as well as crucial details of each, which need to be taken into account within the development of a unified model. Main approach is a cluster-virial...

Neutron stars harbor extreme conditions unattainable in terrestrial laboratories, making them ideal candidates to study the equation of state (EoS) of strongly interacting matter. Advancements in the measurements of neutron star masses, radii and tidal deformabilities through electromagnetic and gravitational wave observations have made it feasible to add further constraints on the EoS. In...

Experiments carried out with HADES (High Acceptance DiElectron Spectrometer) measure products of heavy-ion collisions in the beam energy regime of few GeV per nucleon. Its large geometric acceptance and reconstruction efficiency give insight into the extremely hot and dense nuclear matter produced in such reactions. The focal point of this contribution is the production of charged pions in...

Heavy-ion collisions in the few GeV energy regimes probe similar temperatures and densities as created in neutron star mergers and provide a tool to probe cosmic matter in earthly laboratories \text{[1]}.\ In March 2019, the HADES collaboration recorded 13.7⋅109 Ag(1.58A~GeV)+Ag events as part of the FAIR Phase-0 program. Within this talk, we present preliminary results for yields and...

The exact structure and inner workings of nucleons are debated, since the existence of quarks was postulated. Since then, a lot 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 extend studies to...

At the HADES (High-Acceptance-DiElectron-Spectrometer) experiment, located at the GSI, Darmstadt, the reaction products of relativistic heavy-ion collisions are investigated. The goal is to probe strongly interacting QCD matter that exhibits extreme densities as assumed to be found in merging neutron stars [1].\ In this contribution, results on charged pion emission in the collisions system...

Electromagnetic particles offer a unique opportunity to study the conditions in heavy-ion collisions throughout their whole evolution. Once created, these probes can travel largely unhindered through the strongly interacting medium and bring direct information from their origins to a detector. Virtual photons, decaying into lepton pairs, serve as particularly interesting because they also...

The physics program of the HADES (High Acceptance DiElectron Spectrometer) experiment is focused on investigating properties of strongly interacting matter at moderate temperatures and large baryo-chemical potential. One of the important observables is the study of virtual photons and their decays into electron pairs (e−+e+) in hadron and heavy-ion collisions. As leptons are not affected by...

The Dielectron Spectrometer HADES operated at the SIS18 synchrotron, GSI Darmstadt recently provided new intriguing results on production of electron pairs and of strangeness from nucleus-nucleus collisions, as well as from elementary reactions, in energy region of 1−2~A~GeV. In 2019 the spectrometer was complemented by an electromagnetic calorimeter based on lead-glass modules, which allows...

The pion-nucleus reaction is an important source of information about hadronic matter. At incident momenta below 2 GeV/c, it gives access in a very unique way to the properties of baryonic resonances in the nuclear medium. While the region of the Δ(1232) resonance, corresponding to incident pion beam momenta of about 300 MeV/c, was studied in detail in the past, only very scarce measurements...

ALICE (A Large Ion Collider Experiment) at the CERN Large Hadron Collider (LHC) is designed to study proton-proton and heavy-ion collisions at ultra-relativistic energies. The main goal of the experiment is to assess the properties of quark gluon plasma, a state of matter where quarks and gluons are de-confined, reached in extreme conditions of temperature and energy density. During the...

As part of the FAIR phase-0, the HADES experiment underwent a hardware upgrade that included updating existing components, data-acquisition systems, and the integration of new detectors. In particular, the new Straw Tracking Stations (STS) enlarge the HADES acceptance to low polar angles, crucial for the FAIR phase-0 physics program, including hyperon reconstruction. The STS stations have four...

Track reconstruction is essential for a meaningful physics analysis of data from complex detectors such as PANDA. For hyperon detection this task is even more challenging because hyperons typically fly several centimeters before they decay. Therefore, a secondary track finder for PANDA's barrel part will be presented. This algorithm, the ApolloniusTripletTrackFinder, is the only algorithm...

The upcoming Compressed Baryonic Matter (CBM) experiment will explore the phase diagram of QCD matter at the highest baryon densities. The experiment is expected to run at an unprecedented event rate of up to 10 MHz, resulting in about 1 TB/s of free-streaming raw data. This demands the development of novel analysis techniques to quickly identify the event characteristics and select...

The main goal of the CBM experiment is to study highly compressed baryonic matter produced in collisions of heavy ions. The SIS-100 accelerator at FAIR will enable investigation of the QCD matter at temperatures up to about 120 MeV and net baryon densities 5-6 times the normal nuclear density. Hyperons produced during the dense phase of a heavy-ion collision provide information about the...

The Compressed Baryonic Matter (CBM) experiment at FAIR will investigate the QCD phase diagram at high net-baryon density (µB > 400 MeV) in the energy range of √sNN = 2.7−4.9 GeV. Precise determination of dense baryonic matter properties requires multi-differential measurements of strange hadron yields, both for most copiously produced kaons and Λ as well as for rare (multi-)strange hyperons...

The understanding of the fundamental constituent of nucleons and the internal parton dynamics is one of main goal in modern physics. However, the description of the nucleon structure in the Quantum Chromodynamics (QCD) remains one of the most outstanding challenges in modern high energy and particle physics. Parton distribution and fragmentation functions are used to describe the distribution...

We present a data-driven analysis of the γγ→D+D− and γγ→D0D¯0 reactions from threshold up to 4.0 GeV in the DD¯ invariant mass. For the S-wave contribution, we adopt a partial-wave dispersive representation, which is solved using the N/D ansatz. The left-hand cuts are accounted for using the model-independent conformal expansion. The D-wave χc2(3930) state is described as a Breit-Wigner...

The Belle II experiment at the SuperKEKB energy-asymmetric 𝑒+𝑒− collider is a substantial upgrade of the B factory facility at KEK in Tsukuba, Japan. The experiment began operation in 2019 and has collected 267 fb-1 so far. Belle II is uniquely capable of studying the so-called "XYZ" particles: heavy exotic hadrons consisting of more than three quarks. Moreover the bottomonium sector offers an...

Many proposed and on-going experiments require the preliminary knowledge of low-energy production cross-sections of different onium and/or exotic states in hadronic e.g. in proton-antiproton collisions, to be able to make estimates to the expected yields, momentum distributions etc. These are necessary ingredients to simulate the detector systems, and to plan the experiments. Here, we propose...

In this talk I will provide an overview of the lattice formulation of Quantum Chromodynamics (QCD). I will discuss the methods and observables that play a major role in the study of QCD thermodynamics on the lattice. I will focus on results at finite temperature, and weigh in on the achievements and obstacles that the lattice community deals with at the moment. In particular, I will talk about...

We summarize recent results on the volume dependence of the location of the critical endpoint in the QCD phase diagram. To this end, we employ a sophisticated combination of Lattice Yang-Mills theory and a (truncated) version of Dyson-Schwinger equations in Landau gauge for 2 + 1 quark flavors. We study this system at small and intermediate volumes and determine the dependence of the location...

We summarize a truncation-independent method to compute the equation of state within functional continuum approaches. First, its viability and reliability is demonstrated using a two-flavor Nambu-Jona-Lasinio model in mean-field approximation. Second, the method is applied to solutions obtained from a set of truncated Dyson-Schwinger equations for the nonperturbative quark and gluon...

The open science movement aims at more open and collaborative research practices in which data, software, and other types of academic output are shared and made available for reuse leading to greater scientific and societal impact. Within the nuclear and particle physics communities, the complexity of the analysis codes and the volume of the collected data are the most common obstacles to...

QCD with heavy dynamical quarks exhibits a first order thermal transition which is driven by the spontaneous breaking of the global Z_3 center symmetry. Decreasing the quark masses weakens the transition until the corresponding latent heat vanishes at the critical mass. We explore the heavy mass region with three flavors of staggered quarks and analyze the Polyakov loop and its moments in a...

Quenched QCD at zero baryonic chemical potential undergoes a first-order deconfinement phase transition at a critical temperature Tc, which is related to the spontaneous breaking of the global center symmetry. The center symmetry is broken explicitly by including dynamical quarks, which weaken the first-order phase transition for decreasing quark masses. At a certain critical quark mass, which...

Nuclear physics is key to address fundamental questions related to the origin of the elements, the structure of matter, as well as fundamental symmetries of nature. The advent of new radioactive-beam facilities such as FAIR, together with the urgent need to interpret recent astrophysical observations, now make it essential to provide a predictive description of nuclear properties across the...

The 'island' of fission isomers identified in the actinide region (Z = 92 - 97, N = 141- 151) originates from the multi-humped fission barriers, which can be described as the result of superimposing microscopic shell corrections to the macroscopic liquid drop barrier. For the first time, fission isomers were studied using the fragmentation of 1 GeV/u 238U projectiles rather than light-particle...

We study the interaction of leading jet partons in a strongly interacting quark-gluon plasma (sQGP) medium based on the effective dynamical quasi-particle model (DQPM). The DQPM describes the non-perturbative QCD nature of the sQGP at finite temperature T and baryon chemical potential μB based on a propagator representation in terms of massive off-shell partons (quarks and gluons) which...

Despite the recent experimental and theoretical progress in the investigation of the nuclear fission process, a complete description still represents a challenge in nuclear physics because it is a very complex dynamical process, whose description involves the coupling between intrinsic and collective degrees of freedom as well as different quantum-mechanical phenomena. Due to this complexity...

Delbrück scattering is the process in which a photon is elastically scattered by an atomic nucleus via the production of virtual electron-positron pairs. It is one of the few non-linear quantum electrodynamical processes that can be observed experimentally and, hence, testing the respective theoretical predictions serves as an important test of QED in strong electromagnetic fields. Despite the...

We recently devised a methodology within automatic differentiation (AD) which integrates our physics-priors into the specific IPs and deep learning representation together to perform Bayesian inference on the IPs. We demonstrated the developed methodology in several IPs raised in high energy nuclear physics (can also be easily generalized to other physics areas as well). (1) We first deploy...

We discuss recent lattice gauge theory results from an ongoing project concerned with the computation of spin and mass dependent heavy quark-antiquark potentials. These potentials are then used in a Schrödinger eq

We reconstruct effective spectral functions of the ρ-meson in different scenarios via lifetime analysis using the hadronic transport SMASH (Simulating Many Accelerated Strongly-interacting Hadrons). The theoretical interest in the behavior of in-medium spectral functions lies in the expected restoration of chiral symmetry at high energy densities, which may be accessed experimentally by...

Understanding the phase diagram of QCD by measuring fluctuations of conserved charges in heavy-ion collision is one of the main goals of the beam energy scan program at RHIC. For a precise measurement of the cumulants it is necessary to grasp the role of charge conservation in heavy-ion collision measurements. Within this work, we calculate the role of hadronic interactions and momentum cuts...

The Compressed Baryonic Matter experiment (CBM) aims to study the area of the QCD phase diagram at high net baryon densities and moderate temperatures. It is predicted by Three-fluid Hydrodynamics-based Event Simulator (THESEUS) that one of the signatures of phase transition is a change in shape of the mid-rapidity curvature and yield. In this contribution we will present CBM performance for...

The NA60+ experiment is designed to study the phase diagram of strongly interacting matter by measuring thermal dimuons, charm, and strange particles produced in ultra-relativistic heavy-ion collisions. NA60+ will be installed at the CERN SPS, allowing an energy scan in the range sNN−−−−√∼5−17 GeV and studying a region of high baryonic density little explored so far. The apparatus will be...

The production mechanism of (anti)nuclei in ultrarelativistic hadronic collisions is under intense debate in the scientific community. The description of the experimental measurements is currently based on two competing phenomenological models: the statistical hadronisation model and the coalescence approach. Light (anti)(hyper)nuclei have been extensively measured in small collision systems...

One of the most challenging questions about the smallest constituents of visible matter is how hadrons are build from quarks. This means we do not yet understand the structure of one of the most abundant particles of our world, the nucleon. But what if we change the nucleon a little bit? Would that extend our picture? Hyperons are similar to nucleons but contain one or several strange quarks....

Since the discovery of tetraquarks, there has been a lot of excitement around this topic from the theoretical as well as the experimental side. To study the poperties of these 4-quark states we use a functional framework which combines (truncated) Dyson-Schwinger and Bethe-Salpeter equations in Landau gauge. This approach allows us to extract qualitative results for mass spectra, decay widths...

The open science movement aims at more open and collaborative research practices in which data, software, and other types of academic output are shared and made available for reuse leading to greater scientific and societal impact. Within the nuclear and particle physics communities, the complexity of the analysis codes and the volume of the collected data are the most common obstacles to...