This report describes the physics case, the resulting detector requirements, and the
evolving detector concepts for the experimental program at the Electron-Ion Col-
lider (EIC). The EIC will be a powerful new high-luminosity facility in the United
States with the capability to collide high-energy electron beams with high-energy
proton and ion beams, providing access to those regions in the nucleon and nu-
clei where their structure is dominated by gluons. Moreover, polarized beams in
the EIC will give unprecedented access to the spatial and spin structure of the
proton, neutron, and light ions. The studies leading to this document were com-
missioned and organized by the EIC User Group with the objective of advancing
the state and detail of the physics program and developing detector concepts that
meet the emerging requirements in preparation for the realization of the EIC. The
effort aims to provide the basis for further development of concepts for experimen-
tal equipment best suited for the science needs, including the importance of two
complementary detectors and interaction regions.
This report consists of three volumes. Volume I is an executive summary of our
findings and developed concepts. In Volume II we describe studies of a wide range
of physics measurements and the emerging requirements on detector acceptance
and performance. Volume III discusses general-purpose detector concepts and the
underlying technologies to meet the physics requirements. These considerations
will form the basis for a world-class experimental program that aims to increase
our understanding of the fundamental structure of all visible matter.
