Lepton scattering is an established ideal tool for studying inner structure of small particles
such as nucleons as well as nuclei. As a future high energy nuclear physics project, an …

The quark model was formulated in 1964 to classify mesons as bound states made of a
quark–antiquark pair, and baryons as bound states made of three quarks. For a long time all …

The past seventeen years have witnessed tremendous progress on the experimental and
theoretical explorations of the multiquark states. The hidden-charm and hidden-bottom …

Many efforts have been made to reveal the nature of the overabundant resonant structures
observed by the worldwide experiments in the last two decades. Hadronic molecules attract …

The super τ-charm facility (STCF) is an electron–positron collider proposed by the Chinese
particle physics community. It is designed to operate in a center-of-mass energy range from …

A large number of experimental discoveries especially in the heavy quarkonium sector that
did not meet the expectations of the until then very successful quark model led to a …

The spectrum of hadrons is the manifestation of color confinement of quantum
chromodynamics. Hadronic resonances correspond to poles of the S-matrix. Since 2003 …

1 Executive summary The purpose of this document is to outline the developing scientific
case for pursuing an energy upgrade to 22 GeV of the Continuous Electron Beam …

The last decade has seen a marked shift in how the internal structure of hadrons is
understood. Modern experimental facilities, new theoretical techniques for the continuum …

Tremendous progress has been made experimentally in the hadron spectrum containing
heavy quarks in the last two decades. It is surprising that many resonant structures are …