12,010 research outputs found
Spin-Cherenkov effect in a magnetic nanostrip with interfacial Dzyaloshinskii-Moriya interaction
Spin-Cherenkov effect enables strong excitations of spin waves (SWs) with
nonlinear wave dispersions. The Dzyaloshinskii-Moriya interaction (DMI) results
in anisotropy and nonreciprocity of SWs propagation. In this work, we study the
effect of the interfacial DMI on SW Cherenkov excitations in permalloy
thin-film strips within the framework of micromagnetism. By performing
micromagnetic simulations, it is shown that coherent SWs are excited when the
velocity of a moving magnetic source exceeds the propagation velocity of the
SWs. Moreover, the threshold velocity of the moving magnetic source with finite
DMI can be reduced compared to the case of zero DMI. It thereby provides a
promising route towards efficient SW generation and propagation, with potential
applications in spintronic and magnonic devices.Comment: 6 pages, 5 figures. To be published in Scientific Report
Resolving the Degeneracy in Single Higgs Production with Higgs Pair Production
The Higgs boson production can be affected by several anomalous couplings,
e.g. and anomalous couplings. Precise measurement of
production yields two degenerate parameter spaces of and ; one
parameter space exhibits the SM limit while the other does not. Such a
degeneracy could be resolved by Higgs boson pair production. In this work we
adapt the strategy suggested by the ATLAS collaboration to explore the
potential of distinguishing the degeneracy at the 14 TeV LHC. If the
anomalous coupling is induced only by the operator , then the non-SM-like band could be excluded with an integrated luminosity
of . Making use of the fact that the Higgs boson pair
is mainly produced through an -wave scattering, we propose an analytical
function to describe the fraction of signal events surviving a series of
experimental cuts for a given invariant mass of Higgs boson pair. The function
is model independent and can be applied to estimate the discovery potential of
various NP models
Simple non-Abelian extensions of the standard model gauge group and the diboson excesses at the LHC
The ATLAS collaboration reported excesses at around 2 TeV in the di-boson
production decaying into hadronic final states. We consider the possibility of
explaining the excesses with extra gauge bosons in two simple non-Abelian
extensions of the Standard Model. One is the so-called models with a
symmetry structure of and the other is
the models with an extended symmetry of . The and bosons emerge after the electroweak symmetry is
spontaneously broken. Two patterns of symmetry breaking in the models
are considered in this work: one is , the other is . The symmetry breaking of the model is
. We perform a global
analysis of and phenomenology in ten new physics models,
including all the channels of decay. Our study shows that
the leptonic mode and the dijet mode of decays impose a
very stringent bound on the parameter space in several new physics models. Such
tight bounds provide a useful guide for building new physics models to address
on the diboson anomalies. We also note that the Left-Right and Lepton-Phobic
models can explain the excess if the deviation in
the pair around 2~TeV were confirmed to be a fluctuation of the SM
backgrounds.Comment: Publish version; title changed as suggested by journal Edito
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