TY - JOUR
T1 - Small-x physics
T2 - From HERA to LHC and beyond
AU - Frankfurt, Leonid
AU - Strikman, Mark
AU - Weiss, Christian
N1 - Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2005
Y1 - 2005
N2 - We summarize the lessons learned from studies of hard scattering processes in high-energy electron-proton collisions at HERA and antiproton-proton collisions at the Tevatron, with the aim of predicting new strong interaction phenomena observable in next-generation experiments at the Large Hadron Collider (LHC). Processes reviewed include inclusive deep-inelastic scattering (DIS) at small x, exclusive and diffractive processes in DIS and hadron-hadron scattering, as well as color transparency and nuclear shadowing effects. A unified treatment of these processes is outlined on the basis of factorization theorems of quantum chromodynamics, and using the correspondence between the "parton" picture in the infinite-momentum frame and the "dipole" picture of high-energy processes in the target rest frame. The crucial role of the three dimensional quark and gluon structure of the nucleon is emphasized. A new dynamical effect predicted at high energies is the unitarity, or black disk, limit (BDL) in the interaction of small dipoles with hadronic matter, owing to the increase of the gluon density at small x. This effect is marginally visible in diffractive DIS at HERA and will lead to the complete disappearance of Bjorken scaling at higher energies. In hadron-hadron scattering at LHC energies and beyond (cosmic ray physics), the BDL will be a standard feature of the dynamics, with implications for (a) hadron production at forward and central rapidities in central proton-proton and proton-nucleus collisions, in particular events with heavy particle production (Higgs), (b) proton-proton elastic scattering, and (c) heavy-ion collisions. We also outline the possibilities for studies of diffractive processes and photon-induced reactions (ultraperipheral collisions) at LHC, as well as possible measurements with a future electron-ion collider.
AB - We summarize the lessons learned from studies of hard scattering processes in high-energy electron-proton collisions at HERA and antiproton-proton collisions at the Tevatron, with the aim of predicting new strong interaction phenomena observable in next-generation experiments at the Large Hadron Collider (LHC). Processes reviewed include inclusive deep-inelastic scattering (DIS) at small x, exclusive and diffractive processes in DIS and hadron-hadron scattering, as well as color transparency and nuclear shadowing effects. A unified treatment of these processes is outlined on the basis of factorization theorems of quantum chromodynamics, and using the correspondence between the "parton" picture in the infinite-momentum frame and the "dipole" picture of high-energy processes in the target rest frame. The crucial role of the three dimensional quark and gluon structure of the nucleon is emphasized. A new dynamical effect predicted at high energies is the unitarity, or black disk, limit (BDL) in the interaction of small dipoles with hadronic matter, owing to the increase of the gluon density at small x. This effect is marginally visible in diffractive DIS at HERA and will lead to the complete disappearance of Bjorken scaling at higher energies. In hadron-hadron scattering at LHC energies and beyond (cosmic ray physics), the BDL will be a standard feature of the dynamics, with implications for (a) hadron production at forward and central rapidities in central proton-proton and proton-nucleus collisions, in particular events with heavy particle production (Higgs), (b) proton-proton elastic scattering, and (c) heavy-ion collisions. We also outline the possibilities for studies of diffractive processes and photon-induced reactions (ultraperipheral collisions) at LHC, as well as possible measurements with a future electron-ion collider.
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U2 - 10.1146/annurev.nucl.53.041002.110615
DO - 10.1146/annurev.nucl.53.041002.110615
M3 - Review article
AN - SCOPUS:30144436187
VL - 55
SP - 403
EP - 465
JO - Annual Review of Nuclear and Particle Science
JF - Annual Review of Nuclear and Particle Science
SN - 0163-8998
ER -