9,254 research outputs found
Triple and quartic interactions of Higgs bosons in the two-Higgs-doublet model with CP violation
We consider the two-Higgs-doublet model with explicit CP-violation, where the
effective Higgs potential is not CP-invariant at the tree-level. Three neutral
Higgs bosons of the model are the mixtures of CP-even and CP-odd bosons which
exist in the CP-conserving limit of the theory. The mass spectrum and
tree-level couplings of the neutral Higgs bosons to gauge bosons and fermions
are significantly dependent on the parameters of the Higgs boson mixing matrix.
We calculate the Higgs-gauge boson, Higgs-fermion, triple and quartic Higgs
self-interactions in the MSSM with explicit CP-violation in the Higgs sector
and CP-violating Yukawa interactions of the third generation scalar quarks. In
some regions of the MSSM parameter space substantial changes of the
self-interaction vertices take place, leading to significant suppression or
enhancement of the multiple Higgs boson production cross sections.Comment: 29 pages, 4 figures. Minor changes in section 3, misprints in (47)
corrected. Version accepted by EPJ
Mott-Anderson freeze-out and the strange matter "horn"
We discuss the -dependence of the ratio in heavy-ion
collisions (the "horn" effect) within a Mott-Anderson localization model for
chemical freeze-out. The different response of pion and kaon radii to the hot
and dense hadronic medium results in different freeze-out conditions. We
demonstrate within a simple model that this circumstance enhances the "horn"
effect relative to statistical models with universal chemical freeze-out.Comment: 8 pages, 4 figure
CompHEP 4.4 - Automatic Computations from Lagrangians to Events
We present a new version of the CompHEP program (version 4.4). We describe
shortly new issues implemented in this version, namely, simplification of quark
flavor combinatorics for the evaluation of hadronic processes, Les Houches
Accord based CompHEP-PYTHIA interface, processing the color configurations of
events, implementation of MSSM, symbolical and numerical batch modes, etc. We
discuss how the CompHEP program is used for preparing event generators for
various physical processes. We mention a few concrete physics examples for
CompHEP based generators prepared for the LHC and Tevatron.Comment: The paper has been presented on IX International Workshop on Advanced
Computing and Analysis Techniques in Physics Research December 1-5, 2003.
KEK, Japan. 10 pages, 2 figure
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