Study of the Fundamental Structure of Matter With an Electron-Ion Collider

Abstract

We present an overview of the scientific opportunities that would be offered by a high-energy electron-ion collider. We discuss the relevant physics of polarized and unpolarized electron-proton collisions and of electron-nucleus collisions. We also describe the current accelerator and detector plans for a future electron-ion collider.

Charm parton content of the nucleon

“…Such measurements would be experimentally very challenging, but potentially important [23,24]. The proposed future ep colliders eRHIC [25] and LHeC [26] would also be very helpful for the study of heavy quark parton distributions.…”

Exploring the polarization of gluons in the nucleon

“…We note that a recent new analysis by the COMPASS collaboration [20] using their latest deuteron DIS data [21] finds two "allowed" regions for ∆g, one with positive, one with negative gluon polarization. Clean and precise extractions of ∆g(x, Q 2 ) over a wide range of x and Q 2 from scaling violations of g 1 would become possible at a polarized electron-ion collider, EIC [22], thanks to its vastly larger kinematic reach. Results for x∆g(x, Q 2 = 5 GeV 2 ) from several analyses [16,17,18] of polarized DIS.…”

Exclusive coherent production of heavy vector mesons in nucleus-nucleus collisions at energies available at the CERN Large Hadron Collider

“…From this point of view the coherent diffractive production of vector mesons on heavy nuclei is very interesting. Clearly, the best option to study the small-x nuclear glue would be a dedicated electron-ion collider [3], where for example one could measure nuclear structure functions at perturbatively large Q 2 . Lacking such a facility, there appears to be no easy experimental access to the nuclear gluon distribution.…”