M. S. Berger

s-Channel Higgs Boson Production at a Muon-Muon Collider.

High luminosity muon-muon colliders would provide a powerful new probe of Higgs boson physics through {ital s}-channel resonance production. We discuss the prospects for detection of Higgs bosons and precision measurements of their masses and widths at such a machine.

Particle physics opportunities at μ+μ− colliders

We discuss the capabilities of future muon colliders to resolve important particle physics questions. A collider with c.m. energy √ s = 100 to 500 GeV offers the unique opportunity to produce Higgs bosons in the s -channel and thereby measure the Higgs masses, total widths and several partial widths to high precision. At this same machine, tt and W + W − threshold studies would yield superior precision in the determination of m t and m w . A multi-TeV μ + μ − collider would open up the realm of physics above the 1 TeV scale, allowing, for example, copious production of supersymmetric particles up to the highest anticipated masses or a detailed study of the strongly-interacting scenario of electroweak symmetry breaking.

Precision Higgs boson mass determination at lepton colliders

We demonstrate that a measurement at future colliders of the Bjorken process e{sup +}e{sup -} , {mu}{sup +}{mu}{sup -}{r_arrow}ZH in the threshold region can yield a precise determination of the Higgs boson mass. With an integrated luminosity of 100fb{sup -1} it is possible to measure the standard model Higgs mass to within 45MeV (60MeV) at {mu}{sup +}{mu}{sup -}(e{sup +}e{sup -}) collider for m{sub H}=100GeV. {copyright} {ital 1997} {ital The American Physical Society}

Muon collider physics at very high-energies

Muon colliders might greatly extend the energy frontier of collider physics. One can contemplate circular colliders with center-of-mass energies in excess of 10 TeV. Some physics issues that might be relevant at such a machine are discussed.

Lorentz Violation and Spacetime Supersymmetry

Supersymmetry and Lorentz invariance are closely related as both are spacetime symmetries. Terms can be added to Lagrangians that explicitly break either supersymmetry or Lorentz invariance. It is possible to include terms which violate Lorentz invariance but maintain invariance under supersymmetric transformations. I illustrate this with some simple extensions of the original Wess‐Zumino model.

Precision measurements of threshold chargino production

We analyze the prospects at a muon collider for measuring chargino masses in the μ+μ−→χ+χ− processes in the threshold region. We find that a measurement of the lightest chargino mass to better than 200 MeV is possible with 100 fb−1 luminosity. The muon sneutrino mass can also be simultaneously measured to a few GeV.

Top quark physics at muon and other future colliders

The top quark will be extensively studied at future muon colliders. The threshold cross section can be measured precisely, and the small beam energy spread is especially effective at making the measurement useful. We report on all the activities of the top quark working group, including talks on top quark physics at other future colliders.

LORENTZ VIOLATION IN SUPERSYMMETRIC FIELD THEORIES

Broken spacetime symmetries might emerge from a fundamental physical theory. The effective low-energy theory might be expected to exhibit violations of supersymmetry and Lorentz invariance. Some illustrative models which combine supersymmetry and Lorentz violation are described, and a superspace formulation is given.

SUSY thresholds at a muon collider

One of the useful features of muon colliders is the naturally narrow spread in beam energies. Measurements of threshold cross sections then become a prime candidate for precision measurements of particle masses, widths, and couplings as well as determining particle spin. We describe the potential for measuring cross sections near threshold in supersymmetric theories.