13,362 research outputs found
CP odd anomalous interactions of Higgs boson in its production at Photon Colliders
We discuss the potentialities of the study of CP-odd interactions of the
Higgs boson with photons via its production at gamma-gamma and e-gamma
colliders. Our treatment of H-gamma-gamma and H-Z-gamma anomalous interactions
includes a set of parameters, whose impact on physical observables has not been
considered before. We focus on two reactions - gamma+gamma-->H and e+gamma-->eH
- and introduce the polarization and/or azimuthal asymmetries that are
particularly sensitive to specific features of anomalies. We discuss the ways
of disentangling effects of physically different parameters of anomalies and
estimate what magnitude of CP violating phenomena can be seen in these
experiments.Comment: 17 pages, 9 figs; some modifications in the results presentation;
version to be published in Eur.Phys.J.
Tree-level unitarity constraints in the most general 2HDM
We obtain tree-level unitarity constraints for the most general Two Higgs
Doublet Model (2HDM) with explicit CP-violation. We briefly discuss
correspondence between possible violation of tree level unitarity limitation
and physical content of the theory.Comment: 6 pages, no figure
Higgs masses of the general 2HDM in the Minkowski-space formalism
We study the masses of the Higgs bosons in the most general two-Higgs-doublet
model in a basis-independent approach. We adapt the recently developed
Minkowski-space formalism to this problem and calculate traces of any power of
the mass-matrix in a compact and reparametrization-invariant form. Our results
can be used to gain insight into the dynamics of the scalar sector of the
general 2HDM.Comment: 14 pages, no figures; v2: reference added, misprints correcte
Possible Odderon discovery at HERA via charge asymmetry in the diffractive pi+pi- production
We discuss how the evasive Odderon signal can be enhanced by final state
interactions. We suggest the charge asymmetry of pion spectra in diffractive
pi+pi- photoproduction as a promising signature of the Odderon exchange.Comment: 4 pages, To appear in Proceedings of the 9th International Workshop
on Deep Inelastic Scattering (DIS2001), Bologna, Italy, 27 Apr. - 1 May 200
The evolution of vacuum states and phase transitions in 2HDM during cooling of Universe
We consider the evolution of the ground state in the Two Higgs Doublet Model
during cooling down of the Universe after the Big Bang. Different regions in
the space of free parameters of this model correspond to different sequences of
thermal phase transitions. We discuss different paths of thermal evolution and
corresponding evolution of physical properties of the system for different
modern values of the parameters.Comment: 28 pages, 12 figure
Exclusive production of meson in proton-proton collisions at high energies
First we calculate cross section for the reaction
from the threshold to very large energies. At low energies the pion exchange is
the dominant mechanism. At large energies the experimental cross section can be
well described within the -factorization approach by adjusting
light-quark constituent mass. Next we calculate differential distributions for
the reaction at RHIC, Tevatron and LHC energies for the
first time in the literature. We consider photon-pomeron (pomeron-photon),
photon-pion (pion-photon) as well as diffractive hadronic bremsstrahlung
mechanisms. The latter are included in the meson/reggeon exchange picture with
parameters fixed from the known phenomenology. Interesting rapidity
distributions are predicted. The hadronic bremsstrahlung contributions dominate
at large (forward, backward) rapidities. At small energies the photon-pomeron
contribution is negligible compared to the bremsstrahlung contributions. It
could be, however, easily identified at large energies at midrapidities.
Absorptions effects are included and discussed. Our predictions are ready for
verification at RHIC and LHC.Comment: 21 pages, 14 figure
Spin-engineered quantum dots
Spatially nonhomogeneously spin polarized nuclei are proposed as a new
mechanism to monitor electron states in a nanostructure, or as a means to
createn and, if necessary, reshape such nanostructures in the course of the
experiment. We found that a polarization of nulear spins may lift the spin
polarization of the electron states in a nanostructure and, if sufficiently
strong, leads to a polarization of the electron spins. Polarized nuclear spins
may form an energy landscape capable of binding electrons with energy up to
several meV and the localization radius 100\AA.Comment: 9 pages, 1 figure, submitted to Physica E, Augist 31, 200
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