NSTAR 2026
The 15th International Workshop on the Physics of Excited Nucleons will take place in Seville from September 7th to 11th, 2026.
Nucleon excitations are providing a unique opportunity to explore many facets of the non-perturbative strong interaction and how various baryons, including those with strange and heavy flavor content, emerge from QCD. The rapid growth of high-quality experimental results on exclusive meson photoproduction off nucleons from CLAS, ELSA, GRAAL, LEPS, and MAMI allow us to pin down reaction amplitudes with unprecedented precision and to establish the baryon spectrum with minimal model dependence. Experiments with hadronic beams (GSI, JPARC) and hadron production in e+e- collisions (BES) extend and complement the scope of baryon spectroscopy, where the importance of baryon states in the evolution of the Universe has also just recently been elucidated.
Space-like resonance electrocouplings can be extracted, based mainly on the CLAS data on exclusive meson electroproduction off nucleons, over a wide range of photon virtualities and provide valuable information on the excited nucleon structure by offering access to non-perturbative strong interaction mechanisms behind the N* generation. The insight into the baryon structure is complemented by the studies of time-like form factors (BABAR, BES, GSI, PANDA).
From the theory side, the Dyson-Schwinger-Equation and Lattice-QCD approaches are remarkably progressing in describing the baryon spectrum and structure from the first principles of QCD. New opportunities to explore the full spectrum of excited nucleons as well as strange and heavy baryons have been offered by advances in the QCD-inspired quark models.
Synergistic efforts between experimentalists and theorists have already demonstrated our capability to address some open key problems of hadron physics on the nature of hadron mass, quark-gluon confinement, and their emergence from QCD via the exploration of the baryon structure and spectrum including the search for the new states of hadron matter such as hybrid and 'multi-quark' baryons. The purpose of this workshop is to share the latest results on various aspects of low-energy QCD dynamics in terms of N* resonances, and to discuss the future developments.
Topics covered in the workshop are:
- Baryon spectrum through meson photoproduction
- Baryon resonances in experiments with hadron beams and in the e+e- collisions
- Baryon resonances in ion collisions and their role in cosmology
- Baryon structure through meson electroproduction, transition form factors, and time-like form factors
- Amplitude analyses and baryon parameter extraction
- Baryon spectrum and structure from first principles of QCD
- Advances in the modeling of baryon spectrum and structure
- Facilities and future projects
- Other topics related to N* physics
