Discovery through Complementarity - The EIC 2nd Detector

The Electron-Ion Collider (EIC) is a high-luminosity machine that provides polarized electron beam and a variety of ion beams to study the structure of hadronic matter. The EIC will address some of the most profound questions concerning the emergence of hadron's properties by precisely imaging gluons and quarks inside hadron such as their distributions in space and momentum, their role in building the hadron spin, and the properties of gluons in hadron at high energies.

The EIC collider and its general purpose detector (ePIC) are listed as one of the top priorities in the recent Nuclear Physics Long Range Plan. However, the needs for a second detector are recognized by the community. A second detector is necessary to validate and cross-calibrate potential scientific discoveries through complementary detector designs. Moreover, a second detector could cover EIC physics and kinematic ranges that are less well addressed in the ePIC. For example, the secondary focus integrated into the design of the second interaction region can enhance the acceptance of ion beam fragments and off-momentum ions for exclusive measurements.

This presentation will discuss the benefits of a second detector and the concepts of detector designs.