# Measuring the Higgs CP Property through Top Quark Pair Production at Photon Linear Colliders

ArticleinPhysical Review D 62(11) · May 2000with4 Reads
DOI: 10.1103/PhysRevD.62.115005 · Source: arXiv
Abstract
We present a model-independent study of the effects of a neutral Higgs boson without definite CP-parity in the process $\gamma\gamma \to t\bar{t}$ around the mass pole of the Higgs boson. Near the resonance pole, the interference between the Higgs-exchange and the continuum amplitudes can be sizable if the photon beams are polarized and helicities of the top and anti-top quarks are measured. Study of these interference effects enables one to determine the CP property of the Higgs boson completely. An example of the complete determination is demonstrated in the context of the minimal supersymmetric standard model. Comment: 17 pages, LaTeX file with 1 eps figure
• ##### ECFA/CERN studies of a European Neutrino Factory Complex
Article · · Physical Review D
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• ##### Photon collider at TESLA
[Show abstract] [Hide abstract] ABSTRACT: High energy photon colliders () based on backward Compton scattering of laser light is a very natural addition to e+e− linear colliders. In this report, we consider this option for the TESLA project. Recent study has shown that the horizontal emittance in the TESLA damping ring can be further decreased by a factor of four. In this case, the γγ luminosity in the high energy part of spectrum can reach about (1/3)Le+e−. Typical cross-sections of interesting processes in γγ collisions are higher than those in e+e− collisions by about one order of magnitude, so the number of events in γγ collisions will be more than that in e+e− collisions. Photon colliders can, certainly, give additional information and they are the best for the study of many phenomena. The main question is now the technical feasibility. The key new element in photon colliders is a very powerful laser system. An external optical cavity is a promising approach for the TESLA project. A free electron laser is another option. However, a more straightforward solution is “an optical storage ring (optical trap)” with a diode pumped solid state laser injector which is today technically feasible. This paper briefly reviews the status of a photon collider based on the linear collider TESLA, its possible parameters and existing problems.
Article · Nov 2000
• ##### Neutralino-Nucleus Elastic Cross Section in the Minimal Supersymmetric Standard Model with Explicit CP Violation
[Show abstract] [Hide abstract] ABSTRACT: We study the elastic scattering of the lightest neutralino with a nucleus in the framework of the minimal supersymmetric standard model (MSSM) with explicit flavor preserving CP violation, including the one-loop CP-violating neutral Higgs-boson mixing effects induced dominantly by the CP phases in the top and bottom (s)quark sectors. We construct the most general form of the effective Lagrangian for the neutralino-nucleus scattering in the limit of vanishing momentum transfers and then we perform a comprehensive analysis of the effects of the complex CP phases on the mass spectra of the lightest neutralino, neutral Higgs bosons and top squarks, and on the the spin-dependent and spin-independent neutralino-nucleus scattering cross section for three neucleus targets F, Si and Ge. The CP phases can reduce or enhance the neutralino-nucleus cross sections significantly, depending on the values of the real parameters in the MSSM. Comment: LaTex file of 26 pages with 6 eps figures
Full-text · Article · Dec 2000