170 research outputs found
Electroweak Symmetry Breaking and Higgs Physics
An introduction to electroweak symmetry breaking and Higgs physics is
presented for the Standard Model and its supersymmetric extensions. A brief
overview will also be given on strong interactions of the electroweak gauge
bosons in alternative scenarios. In addition to the theoretical basis, the
present experimental status of Higgs physics and implications for future
experiments at the LHC and linear colliders are discussed.Comment: 70 pages, latex, 30 figure
Measuring Hidden Higgs and Strongly-Interacting Higgs Scenarios
Higgs couplings can be affected by physics beyond the Standard Model. We
study modifications through interactions with a hidden sector and in specific
composite Higgs models accessible at the LHC. Both scenarios give rise to
congruent patterns of universal, or partially universal, shifts. In addition,
Higgs decays to the hidden sector may lead to invisible decay modes which we
also exploit. Experimental bounds on such potential modifications will measure
the concordance of an observed Higgs boson with the Standard Model.Comment: 12 pages, 7 figures; version to be published in Phys. Lett.
Higgs-strahlung and fusion in collisions
Higgs-strahlung and fusion
are the most important mechanisms for the production of Higgs bosons in
collisions at LEP2 and future linear colliders. We have
calculated the cross sections and energy/angular distributions of the Higgs
boson for these production mechanisms. When the boson decays into
(electron-)neutrinos, the two production amplitudes interfere. In the
cross-over region between the two mechanisms the interference term is positive
and of the same size as the individual cross sections, thus enhancing the
production rate.Comment: 9 pages LaTeX2e (using standard graphicx package), 8 figure
Higgs Bosons: Intermediate Mass Range at e+e- Colliders
We elaborate on the production of the Standard Model Higgs particle at
high-energy colliders through the reaction .
Particular emphasis is put on the intermediate mass range. In addition to the
signal we discuss in detail the background processes. Angular distributions
which are sensitive to the spin and parity of the Higgs particle are analyzed.Comment: Standard Latex. 15 pages. 11 figures available by fax or regular
mail. MAD/PH/749, DESY 93-064, UdeM-LPN-TH-93-143, NUHEP-TH-93-1
Heavy flavours and CP violation
The lectures are divided into three parts : 1. Heavy flavours at LEP : test of the Standard Model and the physics beyond. 2. Top quarks at the LHC and high energy e+ e- colliders. 3. CP violation in the standard model and predictions for the b-quark sector.Lectures on CP violations, heavy flavours and the standard mode
Production of Charged Higgs Boson Pairs in Gluon-Gluon Collisions
The search for charged Higgs bosons, which are predicted in supersymmetric theories, is difficult at hadron colliders if the mass is large. In this paper we present the theoretical set-up for the production of charged Higgs boson pairs at the LHC in gluon-gluon collisions: . When established experimentally, the trilinear couplings between charged and neutral CP-even Higgs bosons, and , can be measured
Search for CP Violation in the Decay Z -> b (b bar) g
About three million hadronic decays of the Z collected by ALEPH in the years
1991-1994 are used to search for anomalous CP violation beyond the Standard
Model in the decay Z -> b \bar{b} g. The study is performed by analyzing
angular correlations between the two quarks and the gluon in three-jet events
and by measuring the differential two-jet rate. No signal of CP violation is
found. For the combinations of anomalous CP violating couplings, and , limits of \hat{h}_b < 0.59h^{\ast}_{b} < 3.02$ are given at 95\% CL.Comment: 8 pages, 1 postscript figure, uses here.sty, epsfig.st
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