Physics with e+e− linear colliders

Abstract

We describe the physics potential of e + e − linear colliders in this report. These machines are planned to operate in the first phase at a center-of-mass energy of 500 GeV, before being scaled up to about 1 TeV. In the second phase of the operation, a final energy of about 2 TeV is expected. The machines will allow us to perform precision tests of the heavy particles in the Standard Model, the top quark and the electroweak bosons. They are ideal facilities for exploring the properties of Higgs particles, in particular in the intermediate mass range. New vector bosons and novel matter particles in extended gauge theories can be searched for and studied thoroughly. The machines provide unique opportunities for the discovery of particles in supersymmetric extensions of the Standard Model, the spectrum of Higgs particles, the supersymmetric partners of the electroweak gauge and Higgs bosons, and of the matter particles. High precision analyses of their properties and interactions will allow for extrapolations to energy scales close to the Planck scale where gravity becomes significant. In alternative scenarios, like compositeness models, novel matter particles and interactions can be discovered and investigated in the energy range above the existing colliders up to the TeV scale. Whatever scenario is realized in Nature, the discovery potential of e + e − linear colliders and the high-precision with which the properties of particles and their interactions can be analysed, define an exciting physics programme complementary to hadron machines.

Quantization and Renormalization of the Manifest Left–Right Symmetric Model of Electroweak Interactions

“…In order to break the left-right symmetry to the final U (1) em the Higgs potential is introduced. The most general potential for one bidoublet φ (12) and two triplets ∆ L,R (16) which have the left-right symmetry ) was…”

Electroweak Sudakov form factors and nonfactorizable soft QED effects at NLC energies

“…With next generation of linear colliders (NLC [1]), a new era in the testing of electroweak interactions at the quantum level will begin. In fact, when the c.m.…”

“…Moreover, from a phenomenological point of view, the planned new generation of linear colliders with TeV scale c.m. energy and very high luminosity [1] should be able to test experimentally such structure.…”

Nonrelativistic dynamics of heavy particles near the production threshold

“…The hadron production near heavy quark threshold will be thoroughly studied experimentally at future accelerators, e.g. [1]. The dynamics of a slow moving pair of the heavy quark and antiquark near the production threshold is nonrelativistic to high accuracy that justifies the use of the nonrelativistic quantum mechanics as a proper theoretical framework for describing such a system [2].…”

“…Being much simpler than the comprehensive relativistic treatment this approach allows one to take into account exactly such essential features of the dynamics as Coulomb interaction [3,4]. The spectrum of hadronic states produced near the quark-antiquark threshold is contained in the Green function G(E) = (H − E) −1 of the effective nonrelativistic Hamiltonian H. In the position space it reads G(E; r, r ′ ) = r|(H − E) −1 |r ′ (1) and satisfies the Schrödinger equation…”