26 research outputs found
Higgs boson interference in mu^+ mu^- ->chargino_i chargino_j with longitudinally polarized beams
We study chargino production at a muon collider with longitudinally polarized
beams and center of mass energies around the heavy neutral Higgs boson
resonances. We show that the interference of the CP even and CP odd Higgs
bosons can be analyzed using the energy distributions of the lepton or W boson
from the chargino two-body decays \tilde\chi^\pm_j\to\ell^\mp\tilde\nu_\ell or
\tilde\chi^\pm_j \to W^\pm \neutralino_1, respectively. The energy
distributions depend on the longitudinal polarization of the decaying chargino,
which are correlated to the muon beam polarizations. We define asymmetries in
these energy distributions which allow a determination of the H and A couplings
to the charginos and in particular of their relative phase. We analyze the
asymmetries, cross sections and branching ratios in CP conserving Minimal
Supersymmetric Standard Model scenarios. For nearly degenerate Higgs bosons we
find maximal asymmetries which can be measured with high statistical
significance.Comment: 22 pages, 6 figures, typos corrected and references added, version to
appear in Physical Review
Physics Opportunities at mu+mu- Higgs Factories
We update theoretical studies of the physics opportunities presented by
mu+mu- Higgs factories. Interesting measurements of the Standard Model Higgs
decays into {\bar b}b, tau+tau- and WW* may be possible if the Higgs mass is
less than about 160 GeV, as preferred by the precision electroweak data, the
mass range being extended by varying appropriately the beam energy resolution.
A suitable value of the beam energy resolution would also enable the
uncertainty in the b-quark mass to be minimized, facilitating measurements of
parameters in the MSSM at such a first mu+mu- Higgs factory. These measurements
would be sensitive to radiative corrections to the Higgs-fermion-antifermion
decay vertices, which may violate CP. Radiative corrections in the MSSM may
also induce CP violation in Higgs-mass mixing, which can be probed via various
asymmetries measurable using polarized mu+mu- beams. In addition,
Higgs-chargino couplings may be probed at a second mu+mu- Higgs factory.Comment: Report of the Higgs factory working group of the ECFA-CERN study on
Neutrino Factory & Muon Storage Rings at CERN. 28 p
HI Velocity Fields and Rotation Curves
Wetensch. publicati
CP Studies and Non-Standard Higgs Physics
There are many possibilities for new physics beyond the Standard Model that
feature non-standard Higgs sectors. These may introduce new sources of CP
violation, and there may be mixing between multiple Higgs bosons or other new
scalar bosons. Alternatively, the Higgs may be a composite state, or there may
even be no Higgs at all. These non-standard Higgs scenarios have important
implications for collider physics as well as for cosmology, and understanding
their phenomenology is essential for a full comprehension of electroweak
symmetry breaking. This report discusses the most relevant theories which go
beyond the Standard Model and its minimal, CP-conserving supersymmetric
extension: two-Higgs-doublet models and minimal supersymmetric models with CP
violation, supersymmetric models with an extra singlet, models with extra gauge
groups or Higgs triplets, Little Higgs models, models in extra dimensions, and
models with technicolour or other new strong dynamics. For each of these
scenarios, this report presents an introduction to the phenomenology, followed
by contributions on more detailed theoretical aspects and studies of possible
experimental signatures at the LHC and other colliders.Comment: Report of the CPNSH workshop, May 2004 - Dec 2005, 542 pages. The
complete report as well as its individual chapters are also available from
http://kraml.home.cern.ch/kraml/cpnsh/report.htm