Photon-photon interactions have been an important probe into fundamental particle physics. Until recently, the only way to produce photon-photon collisions was parasitically in the collision of charged particles. Recent advances in short-pulse laser technology have made it possible to consider producing high intensity, tightly focused beams of real photons through Compton scattering. A linear e{sup +}e{sup -} collider could thus be transformed into a photon-photon collider with the addition of high power lasers. In this paper they show that it is possible to make a competitive photon-photon collider experiment using the currently mothballed Stanford Linear Collider. This would produce photon-photon collisions in the GeV energy range which would allow the discovery and study of exotic heavy mesons with spin states of zero and two.

Two-photon physics, i.e. photon-photon collisions in electron-positron colliders, a relatively new field in elementary particle physics, has become very popular in the last 20 years. Many experiments have been performed in this field, and the theoretical implications (in particular in quantum chromodynamics) have been studied in much detail. Nine international workshops devoted to two-photon physics have taken place between 1973 and 1992.This meeting was particularly timely, since a new generation of electron-positron colliders is presently being built or planned. These colliders will involve a large spectrum of beam energies, but their common characteristics should be a high particle flux (luminosity). This should allow for measuring many new phenomena as well as for studying known processes with much higher precision than before. Particularly promising is the prospect of building a dedicated high-energy photon collider; this should become possible using a laser technique allowing for the “conversion” of a linear electron beam into a photon beam.Over 60 physicists (both experimentalists and theorists), mainly from European countries (France, Britain, Italy, Germany, Russia, as well as Sweden and Switzerland), discussed these new possibilities at the above meeting. Over 30 talks were presented and many extended debates took place.

This book is about the dark photon which is a new gauge boson whose existence has been conjectured. Due to its interaction with the ordinary, visible photon, such a particle can be experimentally detected via specific signatures. In this book, the authors review the physics of the dark photon from the theoretical and experimental point of view. They discuss the difference between the massive and the massless case, highlighting how the two phenomena arise from the same vector portal between the dark and the visible sector. A review of the cosmological and astrophysical observations is provided, together with the connection to dark matter physics. Then, a perspective on current and future experimental limits on the parameters of the massless and massive dark photon is given, as well as the related bounds on milli-charged fermions. The book is intended for graduate students and young researchers who are embarking on dark photon research, and offers them a clear and up-to-date introduction to the subject.

The advent of back-scattered laser beams for ee− colliders will allow detailed studies of a large array of high energy [gamma][gamma] and [gamma]e collision processes with polarized beams. These include tests of electroweak theory in photon-photon annihilation such as [gamma][gamma] 2!WW−, [gamma][gamma] 2!Higgs bosons, and higher-order loop processes, such as [gamma][gamma] 2![gamma][gamma], H°Z° and ZZ: Methods for measuring the anomalous magnetic and quadrupole moments of the W and Z gauge bosons to high precision in polarized electron-photon and photon-photon collisions are discussed. Since each photon can be resolved into a W+W− pair, high energy photon-photon collisions can also provide a remarkably background-free laboratory for studying WW collisions and annihilation. I also review high energy [gamma][gamma] and e[gamma] tests of quantum chromodynamics, including the production of two gluon jets in photon-photon collisions, deeply virtual Compton scattering on a photon target, and leading-twist single-spin asymmetries for a photon polarized normal to a production plane. Exclusive hadron production processes in photon-photon collisions provide important tests of QCD at the amplitude level, particularly as measures of hadron distribution amplitudes which are also important for the analysis of exclusive semi-leptonic and two-body hadronic B-decays.

Describes the technology and engineering of the Large Hadron collider (LHC), one of the greatest scientific marvels of this young 21st century. This book traces the feat of its construction, written by the head scientists involved, placed into the context of the scientific goals and principles.

Understanding of protons and neutrons, or "nucleons"â€"the building blocks of atomic nucleiâ€"has advanced dramatically, both theoretically and experimentally, in the past half century. A central goal of modern nuclear physics is to understand the structure of the proton and neutron directly from the dynamics of their quarks and gluons governed by the theory of their interactions, quantum chromodynamics (QCD), and how nuclear interactions between protons and neutrons emerge from these dynamics. With deeper understanding of the quark-gluon structure of matter, scientists are poised to reach a deeper picture of these building blocks, and atomic nuclei themselves, as collective many-body systems with new emergent behavior. The development of a U.S. domestic electron-ion collider (EIC) facility has the potential to answer questions that are central to completing an understanding of atoms and integral to the agenda of nuclear physics today. This study assesses the merits and significance of the science that could be addressed by an EIC, and its importance to nuclear physics in particular and to the physical sciences in general. It evaluates the significance of the science that would be enabled by the construction of an EIC, its benefits to U.S. leadership in nuclear physics, and the benefits to other fields of science of a U.S.-based EIC.