  We investigate dijet production from proton-nucleus collisions at the Large
Hadron Collider (LHC) as a means for observing superfast quarks in nuclei with
Bjorken $x>1$. Kinematically, superfast quarks can be identified through
directly measurable jet kinematics. Dynamically, their description requires
understanding several elusive properties of nuclear QCD, such as nuclear forces
at very short distances, as well as medium modification of parton distributions
in nuclei. In the present work, we develop a model for nuclear parton
distributions at large $x$ in which the nuclear dynamics at short distance
scales are described by two- and three-nucleon short range correlations (SRCs).
Nuclear modifications are accounted for using the color screening model, and an
improved description of the EMC effect is reached by using a structure function
parametrization that includes higher-twist contributions. We apply QCD
evolution at the leading order to obtain nuclear parton distributions in the
kinematic regime of the LHC, and based on the obtained distributions calculate
the cross section for dijet production. We find not only that superfast quarks
can be observed at the LHC, but also that they provide sensitivity to the
practically unexplored three-nucleon SRCs in nuclei. Additionally, the LHC can
extend our knowledge of the EMC effect to large $Q^2$ where higher-twist
effects are negligible.
