8,207 research outputs found
Study of the effective pair interatomic interaction in a Co-Ni melt in terms of the Wills-Harrison model
The dependence of the effective partial Wills-Harrison pair potentials in the equiatomic Co-Ni melt near the melting temperature on the probability of the existence of both diagonal and nondiagonal (in magnetic quantum number) overlappings of d electrons located at different atoms in the molten metal is analyzed. © 2013 Pleiades Publishing, Ltd
MSSM-inspired multifield inflation
Despite the fact that experimentally with a high degree of statistical
significance only a single Standard Model--like Higgs boson is discovered at
the LHC, extended Higgs sectors with multiple scalar fields not excluded by
combined fits of the data are more preferable theoretically for internally
consistent realistic models of particle physics. We analyze the inflationary
scenarios which could be induced by the two-Higgs doublet potential of the
Minimal Supersymmetric Standard Model (MSSM) where five scalar fields have
nonminimal couplings to gravity. Observables following from such MSSM-inspired
multifield inflation are calculated and a number of consistent inflationary
scenarios are constructed. Cosmological evolution with different initial
conditions for the multifield system leads to consequences fully compatible
with observational data on the spectral index and the tensor-to-scalar ratio.
It is demonstrated that the strong coupling approximation is precise enough to
describe such inflationary scenarios.Comment: 27 pages, 4 figures, 5 tables. Version to appear in JHEP. Additions
made to the text of the Introduction dealing with the issues of conformity of
this multifield model and models of N=1 supergravity (pages 2-3). Added new
inflationary scenarios, which are an artifact of such analysis (pages 11-12,
Tables 1-4). Additional comments on page 9 and page 13. New references adde
Kinetic slow mode-type solitons
One-dimensional hybrid code simulations are presented, carried out in order both to study solitary waves of the slow mode branch in an isotropic, collisionless, medium-β plasma (β<sub>i</sub>=0.25) and to test the fluid based soliton interpretation of Cluster observed strong magnetic depressions (Stasiewicz et al., 2003; Stasiewicz, 2004) against kinetic theory. In the simulations, a variety of strongly oblique, large amplitude, solitons are seen, including solitons with Alfvenic polarization, similar to those predicted by the Hall-MHD theory, and robust, almost non-propagating, solitary structures of slow magnetosonic type with strong magnetic field depressions and perpendicular ion heating, which have no counterpart in fluid theory. The results support the soliton-based interpretation of the Cluster observations, but reveal substantial deficiencies of Hall-MHD theory in describing slow mode-type solitons in a plasma of moderate beta
A possible search for Majorana neutrinos at future lepton colliders
We discuss the process , where is
a heavy Majorana neutrino and . Large cross sections are
expected for these processes at high center-of-mass energies, which can be
reached at future lepton-lepton colliders. The Monte Carlo simulation of the
studied processes is produced within the framework of the seesaw type-I model,
where the Majorana neutrinos (or heavy neutral leptons, HNL), are introduced in
the standard leptonic sector. Recently the possibility to search for the direct
HNL production was studied in the process with
the subsequent decay . In this paper we investigate
an alternative process with the lepton number violation by two
units. The similar processes appear in collisions with the same-sign beams,
or . The cross sections of the processes under
consideration are enhanced by the soft photon exchange in the -channel. We
calculate the cross sections for the signals and potential Standard Model
backgrounds for the beam collisions at the 1 TeV center-of-mass energy
and the collisions at 3 TeV and 10 TeV. Due to the diagrams with
soft -channel photons and respective interference the promptly emitted
leptons are produced in the direction close to the corresponding beam. These
leptons will be lost in the beam pipe or badly measured by forward detectors.
However, the signal events can be well separated from backgrounds using the
rest of the event containing the particles. Finally, the expected
upper limits on the mixing parameters as a function of M()
are calculated.Comment: 8 pages, 5 figures, 3 table
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