Workshops

Strong links between theory and experiment are mandatory to advance nuclear physics and optimize the realization of experimental research programs. Presently, there is a limited amount of available data and software that allow experimentalists to have an easy access to state-of-the-art predictions for nuclear observables. One of the goals of the EURO-LABS project, implemented within the Horizon Europe program, consists in establishing virtual access (VA) facilities that fill this gap. The Theo4Exp facility has been recently launched in February 2024. The purpose of this workshop is to make Theo4Exp more widely known, introduce prospective users to its exploitation and, more importantly, set the grounds for broadening the scope of Theo4Exp and ameliorating the service for all the low-energy nuclear physics community. The ultimate goal is, thus, to further improve the synergy between theory and experiment, and improve the scientific impact of the field.

Ab initio applications in nuclear theory have grown dramatically over the past two decades thanks to the rapid development of effective field theories (EFT) for the nuclear force and the introduction of advanced algorithms for large scale many-body computations.

The study of the QCD phase diagram in the high-muB region is a key avenue toward understanding strongly interacting matter under extreme conditions. First accurate data in the collision energy region around 10 GeV, corresponding to baryo-chemical potentials of several hundred MeV, became available recently, with the completion of the Beam Energy Scan at RHIC. Hadronic and electromagnetic observables were the main addressed topics. The next breakthrough is expected with the CBM/HADES experiments at FAIR/GSI and the proposed NA60+ experiment at SPS/CERN that will take data at interaction rates larger by at least two orders of magnitude, allowing a much more accurate study of electromagnetic probes and first results on heavy-quark production. Following an exploratory workshop held at ECT* in 2021, we now aim at substantial progress in reviewing currently available results, analyzing the physics potential of the forthcoming experiments, and discussing first actual predictions for the future measurements. We will also review the progress on new detectors for high-luminosity experiments, identifying possible developments and synergies between the various projects.

The charge radius is a fundamental property of the nucleus, whose knowledge has implications in the development of nuclear structure theory, precision QED tests and searches for physics beyond the Standard model (BSM). Spectroscopy of muonic atoms has produced charge radii with unprecedented precision. Laser spectroscopy is the leading technology to determine charge radii of H and He, while low temperature microcalorimeters as metallic magnetic calorimeters allow a ten-fold improvement for the lightest nuclei (up to Z~10). On the theory side, progress depends critically on a better understanding of nucleon and nuclear polarizabilities, which traditionally constitute the main systematic limitation. The aim of this workshop is to discuss the innovative technologies for high-resolution X-ray spectroscopy, and to discuss necessary improvements on the theoretical side, required to match the experimental accuracies. In addition, perspectives for testing BSM will be presented.

The study of strong-coupling phenomena in quantum field theory has been under particularly intensive study in recent years, with new insights coming from both analytic and numerical innovations. This one-week meeting will bring together scientists from the analytic and numerical communities for a short but intensive workshop to exchange ideas and strengthen collaborations between researchers using different theoretical approaches, ranging from Monte Carlo methods, insights from generalized symmetries and anomalies, topological phases of matter, tensor networks, machine learning and other methods. We plan to have a few talks each day with lots of time for informal discussions between the workshop participants.

With the advent of quantum computers and the recent developments in tensor network methods, Hamiltonian Lattice Gauge Theories have gained renewed interest: The quest is to find efficient formulations of (non-)Abelian lattice gauge theories, which can be facilitated in current and future Hamiltonian simulations. The promise is the ability to investigate problems not accessible to stochastic simulation methods, such as systems at non-zero matter density, topological terms or realtime phenomena. The workshop aims to bring researchers working on these questions together and discuss the most recent algorithmic and methodological developments as well as results for various applications in the field.

A recent analysis of finite temperature lattice QCD data has provided promising estimates on the location of the critical point. This analysis builds upon our improved understanding of the QCD analytic structure in the plane of complex chemical potential, with the Yang-Lee edge singularity serving as a key reference point. The prediction of the QCD critical point position involved tracing and extrapolating the trajectory of the Yang-Lee singularities as a function of temperature. This workshop aims to bring together the lattice QCD and pure theory communities to critically evaluate the reliability of this analysis and develop a strategy to minimize systematic errors in determining the position of the QCD critical point.

Understanding thermalization dynamics of QCD in ultrarelativistic nuclear collisions at RHIC and LHC is a largely open question of fundamental importance. Current theoretical understanding is based on progress in simulating time evolution of non-Abelian gauge theories that occurred over the past 15 years. The emerging theoretical picture features prominently two attractor phenomena governing information loss about earlier stages of post-collision evolution of nuclear matter: nonthermal fixed points and hydrodynamic attractors. The first aim of the workshop is to decisively advance the topic of thermalization in ultrarelativistic collisions by discussing cutting edge ideas allowing to extend the attractor-based picture of thermalization beyond its current limitations. The second aim of the workshop is to facilitate interdisciplinary exchange of ideas between the communities of nonthermal fixed points, hydrodynamic attractors and cold quantum gases, which provided a platform to experimentally realize nonthermal fixed points and may realize hydrodynamic attractors in the future.

Superconducting devices have gained increasing attention over the past decade as powerful platforms for quantum optics as well as quantum information processing. In particular, superconducting circuits based on non-linear elements, such as Josephson junctions and high kinetic inductance materials, are opening up a new regime for quantum optics experiments at microwave frequencies and quantum analog simulators. The workshop "Superconducting Quantum Devices for Quantum Optics and Quantum Simulations" will address: (i) microwave quantum optics for circuit-QED experiments, (ii) quantum simulation based on superconducting circuits for nuclear physics applications; and (iii) novel detector concepts for astrophysics and particle physics. The workshop aims at bringing together young and senior researchers in the field, as well as international theoreticians and experimentalists to foster exchange and spark ideas for new projects and collaborations, advancing the field of superconducting quantum devices.

The study of short-lived states, whether at the edge of nuclear stability or just above a reaction threshold, represents a complex and multifaceted domain where few-body physics emerges from the interactions of many nucleons. Recent years have seen a surge in experimental observations that continue to challenge our current models of the nucleus. As instrumentation advances rapidly, a widening gap has emerged between nuclear modeling capabilities and the data being collected.