75,863,381 research outputs found
Supersymmetry Breaking in Warped Geometry
We examine the soft supersymmetry breaking parameters in supersymmetric
theories on a slice of AdS_5 which generate the hierarchical Yukawa couplings
by dynamically localizing the bulk matter fields in extra dimension. Such
models can be regarded as the AdS dual of the recently studied 4-dimensional
models which contain a supersymmetric CFT to generate the hierarchical Yukawa
couplings. In such models, if supersymmetry breaking is mediated by the bulk
radion superfield and/or some brane chiral superfields, potentially dangerous
flavor-violating soft parameters can be naturally suppressed, thereby avoiding
the SUSY flavor problem. We present some models of radion-dominated
supersymmetry breaking which yield a highly predictive form of soft parameters
in this framework.Comment: 17 pages, no figures, uses JHEP clas
MAGIC observations of MWC 656, the only known Be/BH system
Context: MWC 656 has recently been established as the first observationally
detected high-mass X-ray binary system containing a Be star and a black hole
(BH). The system has been associated with a gamma-ray flaring event detected by
the AGILE satellite in July 2010. Aims: Our aim is to evaluate if the MWC 656
gamma-ray emission extends to very high energy (VHE > 100 GeV) gamma rays.
Methods. We have observed MWC 656 with the MAGIC telescopes for 23 hours
during two observation periods: between May and June 2012 and June 2013. During
the last period, observations were performed contemporaneously with X-ray
(XMM-Newton) and optical (STELLA) instruments. Results: We have not detected
the MWC 656 binary system at TeV energies with the MAGIC Telescopes in either
of the two campaigns carried out. Upper limits (ULs) to the integral flux above
300 GeV have been set, as well as differential ULs at a level of 5% of
the Crab Nebula flux. The results obtained from the MAGIC observations do not
support persistent emission of very high energy gamma rays from this system at
a level of 2.4% the Crab flux.Comment: Accepted for publication in A&A. 5 pages, 2 figures, 2 table
Integrable discrete autonomous quad-equations admitting, as generalized symmetries, known five-point differential-difference equations
In this paper we construct the autonomous quad-equations which admit as
symmetries the five-point differential-difference equations belonging to known
lists found by Garifullin, Yamilov and Levi. The obtained equations are
classified up to autonomous point transformations and some simple
non-autonomous transformations. We discuss our results in the framework of the
known literature. There are among them a few new examples of both sine-Gordon
and Liouville type equations.Comment: 27 page
Darboux integrability of trapezoidal and families of lattice equations I: First integrals
In this paper we prove that the trapezoidal and the families
of quad-equations are Darboux integrable systems. This result sheds light on
the fact that such equations are linearizable as it was proved using the
Algebraic Entropy test [G. Gubbiotti, C. Scimiterna and D. Levi, Algebraic
entropy, symmetries and linearization for quad equations consistent on the
cube, \emph{J. Nonlinear Math. Phys.}, 23(4):507543, 2016]. We conclude with
some suggestions on how first integrals can be used to obtain general
solutions.Comment: 34 page
Complexity and integrability in 4D bi-rational maps with two invariants
In this letter we give fourth-order autonomous recurrence relations with two
invariants, whose degree growth is cubic or exponential. These examples
contradict the common belief that maps with sufficiently many invariants can
have at most quadratic growth. Cubic growth may reflect the existence of
non-elliptic fibrations of invariants, whereas we conjecture that the
exponentially growing cases lack the necessary conditions for the applicability
of the discrete Liouville theorem.Comment: 16 pages, 2 figure
A multiple scales approach to maximal superintegrability
In this paper we present a simple, algorithmic test to establish if a
Hamiltonian system is maximally superintegrable or not. This test is based on a
very simple corollary of a theorem due to Nekhoroshev and on a perturbative
technique called multiple scales method. If the outcome is positive, this test
can be used to suggest maximal superintegrability, whereas when the outcome is
negative it can be used to disprove it. This method can be regarded as a finite
dimensional analog of the multiple scales method as a way to produce soliton
equations. We use this technique to show that the real counterpart of a
mechanical system found by Jules Drach in 1935 is, in general, not maximally
superintegrable. We give some hints on how this approach could be applied to
classify maximally superintegrable systems by presenting a direct proof of the
well-known Bertrand's theorem.Comment: 30 pages, 4 figur
Next-to-leading order QCD predictions for W+W+jj production at the LHC
Because the LHC is a proton-proton collider, sizable production of two
positively charged W-bosons in association with two jets is possible. This
process leads to a distinct signature of same sign high-pt leptons, missing
energy and jets. We compute the NLO QCD corrections to the QCD-mediated part of
pp -> W+W+jj. These corrections reduce the dependence of the production
cross-section on the renormalization and factorization scale to about +- 10
percent. We find that a large number of W+W+jj events contain a relatively hard
third jet. The presence of this jet should help to either pick up the W+W+jj
signal or to reject it as an unwanted background.Comment: 15 pages, 5 (lovely) figures, v3 accepted for publication in JHEP,
corrects tables in appendi
Porous zinc oxide nanocrystalline film deposition by atmospheric pressure plasma: Fabrication and energy band estimation
Porous ZnO nanocrystalline films have drawn research attention due to improvement in gas sensing, adsorption, photocatalytic, and photovoltaic applications. However, scalable synthesis of porous nanostructures has been a challenge. Here, This paper reports a very easy, fast, and scalable one-step process for synthesis and deposition of porous ZnO nanocrystalline film by low-temperature atmospheric pressure plasma. The plasma is generated with radio frequency power using a metallic zinc wire as a precursor. Nanostructures have been synthesized and agglomerate to form a porous film at the substrate. Energy band structure of the deposited film has been investigated to understand the corresponding band alignment, which is relevant to many applications. An in-depth study of the grown nanostructured ZnO film has been included and characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, kelvin probe measurement, ultra-violet/visible absorption, and photoluminescence
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