Methods to simulate physics systems simultaneously across a range of temperatures provide a natural way to study thermodynamic phases, phase transitions, and criticality in many systems. These multi-canonical methods already represent a very promising approach for upcoming lattice field theory (LFT) calculations, and ongoing research is working towards achieving state-of-the-art applications. Recently, additional momentum has been generated by new connections to machine learning (ML) methods. This workshop aims to bring together the community of researchers working on developments in multi-canonical methods, both within LFT and in other domains, with the objective of cross-pollinating ideas and identifying future directions for this field. Key topics to be discussed include density-of-states methods, nested sampling, parallel tempering, out-of-equilibrium simulation, and connections to flow and diffusion ML models.

The search of neutrinoless double-β decay involves substantial effort from both experimental and theoretical researchers. This yet-unobserved process requires highly sensitive detectors on the experimental side, and computationally intensive, high-precision calculations of the nuclear matrix element on the theoretical side.

The study of charmonium, a system containing a charm quark-anti-quark pair underwent a revolution after a number of entirely unexpected narrow resonances called the Xs, Ys and Zs were discovered by experiments at the start of the new millennium. The nature of these resonances is still unclear. Similarly, interest in glueballs, hadrons made predominantly of confined gluons, has recently been rekindled.

The Electron-Ion Collider (EIC) will open a new frontier in exploring the internal dynamics of hadrons and nuclei, offering precision access to the three-dimensional structure of matter. Transverse Momentum Dependent (TMD) distributions are essential tools for interpreting EIC observables, but the theoretical landscape behind them remains fragmented.

The topic of this workshop is the “X17” particle, whose existence has been claimed in a series of recent experiments. In the workshop, the current status of the new experimental research and the new advances of the theoretical studies about this hypothetical particle will be presented and discussed.