Search results for "Coupling"
showing 10 items of 1862 documents
Surface-Wave Coupling to Single Phononic Subwavelength Resonators
2017
International audience; We propose to achieve manipulation of mechanical vibrations at the micron scale by exploiting the interaction of individual, isolated mechanical resonators with surface acoustic waves. We experimentally investigate a sample consisting of cylindrical pillars individually grown by focused-ion-beam-induced deposition on a piezoelectric substrate, exhibiting different geometrical parameters and excited by a long-wavelength surface elastic wave. The mechanical displacement is strongly confined in the resonators, as shown by field maps obtained by laser scanning interferometry. A tenfold displacement field enhancement compared to the vibration at the surface is obtained, r…
Purcell factor for a point-like dipolar emitter coupled to a two-dimensional plasmonic waveguide
2011
International audience; We theoretically investigate the spontaneous emission of a point-like dipolar emitter located near a two-dimensional plasmonic waveguide of arbitrary form. We invoke an explicit link with the density of modes of the waveguide describing the electromagnetic channels into which the emitter can couple. We obtain a closed form expression for the coupling to propagative plasmon, extending thus the Purcell factor to plasmonic configurations. Radiative and nonradiative contributions to the spontaneous emission are also discussed in detail.
Coupling MCNP-DSP and LAHET Monte Carlo Codes for Designing Subcriticality Monitors for Accelerator-Driven Systems
2001
The design of reactivity monitoring systems for accelerator-driven systems must be investigated to ensure that such systems remain subcritical during operation. The Monte Carlo codes LAHET and MCNP-DSP were combined together to facilitate the design of reactivity monitoring systems. The coupling of LAHET and MCNP-DSP provides a tool that can be used to simulate a variety of subcritical measurements such as the pulsed neutron, Rossi-α, or noise analysis measurements.
High-order harmonic emission from a three-level atom in a laser field
1999
Abstract The spectrum emitted by a three-level atom in the presence of a weak laser field is given together with the population dynamics and the phase of the Fourier transform of the acceleration. Calculations show that the spectrum can be very different from that emitted by a two-level atom. When the trapping conditions are obtained, the coupling to the third level can result in a large change in the spectrum.
Dynamics of a two-state system through a real level crossing
2015
The dynamics of a two-state system whose energies undergo a real crossing at some instant of time is studied. At this instant, both the coupling and the detuning vanish simultaneously, which leads to an exact degeneracy of the eigenenergies of the system. It is found that the dynamics of the system is primarily determined by the manner in which the degeneracy occurs. This interesting behavior is reminiscent of a symmetry breaking process, since the totally symmetric situation occurring at the crossing is significantly altered by infinitesimal quantities, which remove the degeneracy, with very important dynamical implications from there on. A very simple analytical formula is derived, which …
Implementing consistent NLO factorization in single inclusive forward hadron production
2017
Single inclusive forward hadron production in high-energy hadron collisions can provide an important test of the Color Glass Condensate picture at small $x$. Recent studies of this process at next-to-leading order have led to problematic results, with cross sections becoming negative at large transverse momenta. We study a new formulation of this quantity proposed recently by Iancu et al. We show that it leads to physical results up to large transverse momenta at fixed coupling. Taking into account running coupling effects in a way that is consistent with existing DIS calculations still poses a challenge.
Semileptonic Λb→ν¯llΛc(2595) and Λb→ν¯llΛc(2625) decays in the molecular picture of Λc(2595) and Λc(2625)
2017
We evaluate the partial decay widths for the semileptonic ${\mathrm{\ensuremath{\Lambda}}}_{b}\ensuremath{\rightarrow}{\overline{\ensuremath{\nu}}}_{l}l{\mathrm{\ensuremath{\Lambda}}}_{c}(2595)$ and ${\mathrm{\ensuremath{\Lambda}}}_{b}\ensuremath{\rightarrow}{\overline{\ensuremath{\nu}}}_{l}l{\mathrm{\ensuremath{\Lambda}}}_{c}(2625)$ decays from the perspective that these two ${\mathrm{\ensuremath{\Lambda}}}_{c}^{*}$ resonances are dynamically generated from the $DN$ and ${D}^{*}N$ interaction with coupled channels. We find that the ratio of the rates obtained for these two reactions is compatible with present experimental data and is very sensitive to the ${D}^{*}N$ coupling, which becomes…
Hindered (Δl=0) Alpha Decay and Shape Staggering in191Po
1999
Two $\ensuremath{\alpha}$-decaying isomeric states were observed in ${}^{191}\mathrm{Po}$ with ${E}_{\ensuremath{\alpha}}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}7334(10)\mathrm{keV}$ and $\mathrm{T}{}_{1/2}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}22(1)\mathrm{ms}$ for ${}^{191g}\mathrm{Po}$ and $\mathrm{E}{}_{\ensuremath{\alpha}}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}7378(10)\mathrm{keV}$ and $\mathrm{T}{}_{1/2}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}98(8)\mathrm{ms}$ for ${}^{191m}\mathrm{Po}$. Evidence was found for fine-structure decay to excited levels in the ${}^{187}\mathrm{Pb}$ daughter nucleus. The tentative interpretation of these new lev…
Search for three body pion decays π+→l+νX
2021
The three body pion decays π+→l+νX(l=e,μ), where X is a weakly interacting neutral boson, were searched for using the full data set from the PIENU experiment. An improved limit on Γ(π+→e+νX)/Γ(π+→μ+νμ) in the mass range 0<mX<120 MeV/c2 and a first result for Γ(π+→μ+νX)/Γ(π+→μ+νμ) in the region 0<mX<33.9 MeV/c2 were obtained. The Majoron-neutrino coupling model was also constrained using the current experimental result of the π+→e+νe(γ) branching ratio.
Localization vs. Delocalization in Molecules and Clusters: Electronic and Vibronic Interactions in Mixed Valence Systems
1996
The interplay between electron delocalization and magnetic interactions play a key role in areas as diverse as solid state chemistry (bulk magnetic materials, superconductors,...) [1] and biology (iron-sulfur proteins, manganese-oxo clusters ...) [2]. In molecular inorganic chemistry these two electronic processes have been traditionally studied independently. Thus, the electron dynamics has been extensively investigated in mixedvalence dimers [3] as exemplified by the Creutz-Taube complex [(NH3)5RuII(pyrazine)RuIII(NH3)5]. In this kind of molecular complexes one extra electron is delocalized over two diamagnetic metal sites. Therefore, they constitute model systems for the study of the ele…