Search results for "Coupling"
showing 10 items of 1862 documents
Absence of structure in the $^{20,22}$Ne + $^{118}$Sn quasi-elastic barrier distribution
2005
Abstract Motivated by the extreme deformation parameters of the projectile, we have measured quasi-elastic scattering for 20 Ne + 118 Sn. In contrast to calculations based on known collective states, the experimental barrier distribution is structureless. A comparison with the system 22 Ne + 118 Sn shows that this smoothing is unlikely to be due to nucleon- or α -transfer channels, and is more likely to be due to coupling to many other weak channels.
The temperature dependence of vibronic lineshapes: linear electron-phonon coupling.
2014
We calculate the effect of a linear electron-phonon coupling on vibronic transitions of dye molecules of arbitrary complexity. With the assumption of known vibronic frequencies (for instance from quantum-chemical calculations), we give expressions for the absorption or emission lineshapes in a second-order cumulant expansion. We show that the results coincide with those obtained from generalized Redfield theory if one uses the time-local version of the theory and applies the secular approximation. Furthermore, the theory allows to go beyond the Huang-Rhys approximation and can be used to incorporate Dushinsky effects in the treatment of the temperature dependence of optical spectra. We cons…
WS 2 /MoS 2 Heterostructures through Thermal Treatment of MoS 2 Layers Electrostatically Functionalized with W 3 S 4 Molecular Clusters
2020
The preparation of 2D stacked layers combining flakes of different nature gives rise to countless numbers of heterostructures where new band alignments, defined at the interfaces, control the electronic properties of the system. Among the large family of 2D/2D heterostructures, the one formed by the combination of the most common semiconducting transition metal dichalcogenides, WS2 /MoS2 , has awakened great interest owing to its photovoltaic and photoelectrochemical properties. Solution as well as dry physical methods have been developed to optimize the synthesis of these heterostructures. Here, a suspension of negatively charged MoS2 flakes is mixed with a methanolic solution of a cationi…
Towards gauge coupling unification in left-right symmetric SU(3)c×SU(3)L×SU(3)R×U(1)X theories
2017
We consider the possibility of gauge coupling unification within the simplest realizations of the $\mathrm{SU}(3{)}_{\mathrm{c}}\ifmmode\times\else\texttimes\fi{}\mathrm{SU}(3{)}_{\mathrm{L}}\ifmmode\times\else\texttimes\fi{}\mathrm{SU}(3{)}_{\mathrm{R}}\ifmmode\times\else\texttimes\fi{}\mathrm{U}(1{)}_{\mathrm{X}}$ gauge theory. We present a first exploration of the renormalization group equations governing the ``bottom-up'' evolution of the gauge couplings in a generic model with free normalization for the generators. Interestingly, we find that for a $\mathrm{SU}(3{)}_{\mathrm{c}}\ifmmode\times\else\texttimes\fi{}\mathrm{SU}(3{)}_{\mathrm{L}}\ifmmode\times\else\texttimes\fi{}\mathrm{SU}(…
Boundary controlled irreversible port-Hamiltonian systems
2021
Abstract Boundary controlled irreversible port-Hamiltonian systems (BC-IPHS) defined on a 1-dimensional spatial domain are defined by extending the formulation of reversible BC-PHS to irreversible thermodynamic systems controlled at the boundaries of their spatial domain. The structure of BC-IPHS has clear physical interpretation, characterizing the coupling between energy storing and energy dissipating elements. By extending the definition of boundary port variables of BC-PHS to deal with the irreversible energy dissipation, a set of boundary port variables are defined such that BC-IPHS are passive with respect to a given set of conjugated inputs and outputs. As for finite dimensional IPHS…
Spin-orbit, radial, and angular coupling effects in the NaRb excited states
2009
Spin-orbit, radial, and angular nonadiabatic matrix elements between the lowest excited states of NaRb are evaluated by quasi-relativistic ab initio methods, and the results accompanied by potential curves, permanent and transition moments are compared with experimental data and preceding calculations.
The energy dependence of Zweig-rule-violating couplings. A dynamical calculation of ϕ → ρπ
1978
It has been argued that the violation of the Zweig rule is strongly dependent on the kinematical region, especially that it should decrease for large timeliket (asymptotic planarity). We have calculated thet-dependence of the vertex ϕρπ with two different methods, the first one using partial-wave dispersion relations and unitarity and the second one based on FESR and duality. The decrease in the timelike region is confirmed by both calculations. In the spacelike region the energy dependence of the Zweig-rule-violating coupling depends on the method of continuation to off-shell values. We only find an energy dependence if the full amplitude πρ → K $$\bar K$$ is taken into account.
Quantum capture of charged particles by rapidly rotating symmetric top molecules with small dipole moments: analytical comparison of the fly-wheel an…
2013
The rate coefficients for capture of charged particles by spherical top molecules, which by isotopic substitution become symmetric top molecules with small dipole moment, are expressed analytically for the two limiting cases of weak coupling of the molecular angular momentum to the collision axis (dominating Coriolis interaction, the fly-wheel [FW] approximation) and strong coupling (negligible Coriolis interaction, the adiabatic channel [AC] approximation). The comparison leads to relations between rate coefficients for ultra-low (FW) and moderate (AC) temperatures and defines the range of parameters for which the analytical expressions become insufficient and a numerical treatment is nece…
Relative Transition Probability Measurements for Prominent Infrared Spectral Lines of NI
2002
Applying a high-current wall-stabilized arc operated either in helium or in argon always with some admixtures of nitrogen, relative transition probabilities for more than 100 individual spectral lines (fine structure components) have been measured. The studied lines belong mainly to the 3p–3d and 3p–4s transition arrays. Ten lines of the measured set are intersystem transitions. Our data are compared with other experimental results (for about one half of the studied set there are available), with evaluated on the basis of the LS coupling scheme, with semiempirical data, and with recent CIV3 calculations. Some of our results are compared also with experimental data for the next member of the…
Non-Markovian master equation for the XX central spin model
2008
The non-Markovian correlated projection operator technique is applied to the model of a central spin coupled to a spin bath through non uniform XX Heisenberg coupling. The second order results of the Nakajima-Zwanzig and of the time-convolutionless methods are compared with the exact solution considering a fully polarized initial bath state.