High Energy Photon-Photon Collisions at a Linear Collider
Abstract
High intensity back-scattered laser beams will allow the efficient conversion of a substantial fraction of the incident lepton energy into high energy photons, thus significantly extending the physics capabilities of an electron-electron or electron-positron linear collider. The annihilation of two photons produces C=+ final states in virtually all angular momentum states. The annihilation of polarized photons into the Higgs boson determines its fundamental two-photon coupling as well as determining its parity. Other novel two-photon processes include the two-photon production of charged lepton pairs, vector boson pairs, as well as supersymmetric squark and slepton pairs and Higgstrahlung. The one-loop box diagram leads to the production of pairs of neutral particles. High energy photon-photon collisions can also provide a remarkably background-free laboratory for studying possibly anomalous collisions and annihilation. In the case of QCD, each photon can materialize as a quark anti-quark pair which interact via multiple gluon exchange. The diffractive channels in photon-photon collisions allow a novel look at the QCD pomeron and odderon. Odderon exchange can be identified by looking at the heavy quark asymmetry. In the case of electron-photon collisions, one can measure the photon structure functions and its various components. Exclusive hadron production processes in photon-photon collisions test QCD at the amplitude level and measure the hadron distribution amplitudes which control exclusive semi-leptonic and two-body hadronic B-decays.
Cite
@article{arxiv.hep-ph/0404186,
title = {High Energy Photon-Photon Collisions at a Linear Collider},
author = {S. J. Brodsky},
journal= {arXiv preprint arXiv:hep-ph/0404186},
year = {2009}
}
Comments
Invited talk, presented at the 5th International Workshop On Electron-Electron Interactions At TeV Energies, Santa Cruz, California, 12-14 December 2003