3,524 research outputs found
Reply to the Comment of Muessel and Rieger on ``Aging Effects in a Lennard-Jones Glass''
This is a Reply to the Comment of Muessel and Rieger cond-mat/9804063 to out
paper on ``Aging Effects in a Lennerd-Jones Glass''. We show that the scaling
function proposed by Muessel and Rieger does not lead to a satisfactory scaling
of our aging data.Comment: 1 page of Revtex, 1 eps figur
Phenomenology of the General NMSSM with Gauge Mediated Supersymmetry Breaking
We investigate various classes of Gauge Mediated Supersymmetry Breaking
models and show that the Next-to-Minimal Supersymmetric Standard Model can
solve the mu-problem in a phenomenologically acceptable way. These models
include scenarios with singlet tadpole terms, which are phenomenologically
viable, e.g., in the presence of a small Yukawa coupling <~ 10^{-5}. Scenarios
with suppressed trilinear A-terms at the messenger scale lead naturally to
light CP-odd scalars, which play the r\^ole of pseudo R-axions. A wide range of
parameters of such models satisfies LEP constraints, with CP-even Higgs scalars
below 114 GeV decaying dominantly into a pair of CP-odd scalars.Comment: 24 pages, 6 figures, typos corrected, reference adde
Dynamic density functional study of a driven colloidal particle in polymer solutions
The Dynamic Density Functional (DDF) theory and standard Brownian dynamics
simulations (BDS) are used to study the drifting effects of a colloidal
particle in a polymer solution, both for ideal and interacting polymers. The
structure of the stationary density distributions and the total induced current
are analyzed for different drifting rates. We find good agreement with the BDS,
which gives support to the assumptions of the DDF theory. The qualitative
aspect of the density distribution are discussed and compared to recent results
for driven colloids in one-dimensional channels and to analytical expansions
for the ideal solution limit
On massive tensor multiplets
Massive tensor multiplets have recently been scrutinized in hep-th/0410051
and hep-th/0410149, as they appear in orientifold compactifications of type IIB
string theory. Here we formulate several dually equivalent models for massive N
= 1, N=2 tensor multiplets in four space-time dimensions. In the N = 2 case, we
employ harmonic and projective superspace techniques.Comment: 17 pages, LaTeX, no figures; V2: reference adde
Couplings of N=1 chiral spinor multiplets
We derive the action for chiral spinor multiplets coupled to vector and
scalar multiplets. We give the component form of the action, which contains
gauge invariant mass terms for the antisymmetric tensors in the spinor
superfield and additional Green-Schwarz couplings to vector fields. We observe
that supersymmetry provides mass terms for the scalars in the spinor multiplet
which do not arise from eliminating an auxiliary field. We construct the dual
action by explicitly performing the duality transformations in superspace and
give its component form.Comment: 17 pages, v2 small change
Charmed meson decay constants in three-flavor lattice QCD
We present the first lattice QCD calculation with realistic sea quark content
of the D^+ meson decay constant f_{D^+}. We use the MILC Collaboration's
publicly available ensembles of lattice gauge fields, which have a quark sea
with two flavors (up and down) much lighter than a third (strange). We obtain
f_{D^+} = 201 +/- 3 +/- 17 MeV, where the errors are statistical and a
combination of systematic errors. We also obtain f_{D_s} = 249 +/- 3 +/- 16 MeV
for the D_s meson.Comment: note added on recent CLEO measurement; PRL versio
Kondo effect in transport through molecules adsorbed on metal surfaces: from Fano dips to Kondo peaks
The Kondo effect observed in recent STM experiments on transport through CoPc
and TBrPP-Co molecules adsorbed on Au(111) and Cu(111) surfaces, respectively,
is discussed within the framework of a simple model (Phys. Rev. Lett. {\bf 97},
076806 (2006)). It is shown that, in the Kondo regime and by varying the
adequate model parameters, it is possible to produce a crossover from a
conductance Kondo peak (CoPc) to a conductance Fano dip (TBrPP-Co). In the case
of TBrPP-Co/Cu(111) we show that the model reproduces the changes in the shape
of the Fano dip, the raising of the Kondo temperature and shifting to higher
energies of the dip minimum when the number of nearest neighbors molecules is
lowered. These features are in line with experimental observations indicating
that our simple model contains the essential physics underlying the transport
properties of such complex molecules.Comment: 4 pages, 3 figures, submitted to PR
Interactive Learning-Based Realizability for Heyting Arithmetic with EM1
We apply to the semantics of Arithmetic the idea of ``finite approximation''
used to provide computational interpretations of Herbrand's Theorem, and we
interpret classical proofs as constructive proofs (with constructive rules for
) over a suitable structure \StructureN for the language of
natural numbers and maps of G\"odel's system \SystemT. We introduce a new
Realizability semantics we call ``Interactive learning-based Realizability'',
for Heyting Arithmetic plus \EM_1 (Excluded middle axiom restricted to
formulas). Individuals of \StructureN evolve with time, and
realizers may ``interact'' with them, by influencing their evolution. We build
our semantics over Avigad's fixed point result, but the same semantics may be
defined over different constructive interpretations of classical arithmetic
(Berardi and de' Liguoro use continuations). Our notion of realizability
extends intuitionistic realizability and differs from it only in the atomic
case: we interpret atomic realizers as ``learning agents''
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