The 20th COMPASS “Analysis Phase” International Mini-Workshop will take place on October 5, 2026, at CERN in Geneva, Switzerland. The workshop will be held in hybrid mode.
The scientific programme of the COMPASS “Analysis Phase” International Mini-Workshop series covers the broad range of topics traditionally addressed by the COMPASS Collaboration, including:
- Spin and 3D Structure of the Nucleon
- DIS, SIDIS, DVCS, DVMP and Drell-Yan measurements
- TMDs, GPDs and GTMDs
- Fragmentation Functions
- Meson Structure and Spectroscopy
- Searches for Exotics
- Monte-Carlo simulation tools and techniques
- Technical aspects and analysis techniques
The 20th edition will focus in particular on the present status and future prospects of polarized Drell-Yan measurements and their role in studies of the transverse-momentum-dependent structure of the nucleon.
A central question will be whether fundamental universality tests of the TMD framework, most notably the predicted process dependence and sign change of time-reversal-odd TMD distributions between SIDIS and Drell-Yan, remain important and experimentally unresolved scientific goals. We will discuss to what extent existing measurements already provide the necessary answers, where significant uncertainties remain, and which future measurements could have the greatest impact.
The programme will review existing and planned polarized Drell-Yan measurements worldwide, with particular attention to the complementarity of different experimental channels. Proton–proton measurements provide important sensitivity to sea-quark contributions, while pion-nucleon Drell-Yan gives access to the valence-quark region, where effects such as the predicted TMD sign change are expected to be particularly pronounced.
In this context, the workshop will examine the opportunities offered by the CERN M2 beamline, which can provide high-energy pion beams and hosts the former COMPASS experimental area and its successor, the AMBER experiment. The aim is to assess whether a future pion-induced polarized Drell-Yan programme at CERN could make a unique contribution to the global study of nucleon spin and three-dimensional hadron structure.
The workshop will bring together experimentalists, theorists, and phenomenologists and will also contribute to the activities of the COST Action SHARP.
Conference information
