16,179 research outputs found
Test of a universality ansatz for the contact values of the radial distribution functions of hard-sphere mixtures near a hard wall
Recent Monte Carlo simulation results for the contact values of polydisperse
hard-sphere mixtures at a hard planar wall are considered in the light of a
universality assumption made in approximate theoretical approaches. It is found
that the data seem to fulfill the universality ansatz reasonably well, thus
opening up the possibility of inferring properties of complicated systems from
the study of simpler onesComment: 9 pages, 2 figures; v2: minor changes; to be published in the special
issue of Molecular Physics dedicated to the Seventh Liblice Conference on the
Statistical Mechanics of Liquids (Lednice, Czech Republic, June 11-16, 2006
Percus-Yevick theory for the structural properties of the seven-dimensional hard-sphere fluid
The direct correlation function and the (static) structure factor for a
seven-dimensional hard-sphere fluid are considered. Analytical results for
these quantities are derived within the Percus-Yevick theoryComment: 3 pages, 2 tables, 1 figure; v2: minor changes; to be published in
JC
Equation of state of a seven-dimensional hard-sphere fluid. Percus-Yevick theory and molecular dynamics simulations
Following the work of Leutheusser [Physica A 127, 667 (1984)], the solution
to the Percus-Yevick equation for a seven-dimensional hard-sphere fluid is
explicitly found. This allows the derivation of the equation of state for the
fluid taking both the virial and the compressibility routes. An analysis of the
virial coefficients and the determination of the radius of convergence of the
virial series are carried out. Molecular dynamics simulations of the same
system are also performed and a comparison between the simulation results for
the compressibility factor and theoretical expressions for the same quantity is
presented.Comment: 12 pages, 4 figures; v3: Equation (A.19) corrected (see
http://dx.doi.org/10.1063/1.2390712
On the radial distribution function of a hard-sphere fluid
Two related approaches, one fairly recent [A. Trokhymchuk et al., J. Chem.
Phys. 123, 024501 (2005)] and the other one introduced fifteen years ago [S. B.
Yuste and A. Santos, Phys. Rev. A 43, 5418 (1991)], for the derivation of
analytical forms of the radial distribution function of a fluid of hard spheres
are compared. While they share similar starting philosophy, the first one
involves the determination of eleven parameters while the second is a simple
extension of the solution of the Percus-Yevick equation. It is found that the
{second} approach has a better global accuracy and the further asset of
counting already with a successful generalization to mixtures of hard spheres
and other related systems.Comment: 3 pages, 1 figure; v2: slightly shortened, figure changed, to be
published in JC
Gauge-independent Renormalization of the N2HDM
The Next-to-Minimal 2-Higgs-Doublet Model (N2HDM) is an interesting benchmark
model for a Higgs sector consisting of two complex doublet and one real singlet
fields. Like the Next-to-Minimal Supersymmetric extension (NMSSM) it features
light Higgs bosons that could have escaped discovery due to their singlet
admixture. Thereby, the model allows for various different Higgs-to-Higgs decay
modes. Contrary to the NMSSM, however, the model is not subject to
supersymmetric relations restraining its allowed parameter space and its
phenomenology. For the correct determination of the allowed parameter space,
the correct interpretation of the LHC Higgs data and the possible distinction
of beyond-the-Standard Model Higgs sectors higher order corrections to the
Higgs boson observables are crucial. This requires not only their computation
but also the development of a suitable renormalization scheme. In this paper we
have worked out the renormalization of the complete N2HDM and provide a scheme
for the gauge-independent renormalization of the mixing angles. We discuss the
renormalization of the soft breaking parameter and
the singlet vacuum expectation value . Both enter the Higgs self-couplings
relevant for Higgs-to-Higgs decays. We apply our renormalization scheme to
different sample processes such as Higgs decays into bosons and decays into
a lighter Higgs pair. Our results show that the corrections may be sizeable and
have to be taken into account for reliable predictions
Laser induced modulation of the Landau level structure in single-layer graphene
We present perturbative analytical results of the Landau level quasienergy
spectrum, autocorrelation function and out of plane pseudospin polarization for
a single graphene sheet subject to intense circularly polarized terahertz
radiation. For the quasienergy spectrum, we find a striking non trivial
level-dependent dynamically induced gap structure. This photoinduced modulation
of the energy band structure gives rise to shifts of the revival times in the
autocorrelation function and it also leads to modulation of the oscillations in
the dynamical evolution of the out of plane pseudospin polarization, which
measures the angular momentum transfer between light and graphene electrons.
For a coherent state, chosen as an initial pseudospin configuration, the
dynamics induces additional quantum revivals of the wave function that manifest
as shifts of the maxima and minima of the autocorrelation function, with
additional partial revivals and beating patterns. These additional maxima and
beating patterns stem from the effective dynamical coupling of the static
eigenstates. We discuss the possible experimental detection schemes of our
theoretical results and their relevance in new practical implementation of
radiation fields in graphene physics.Comment: 12 pages, 5 figures. Accepted version for publication in Physical
Review
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