Decay channel

The interpretation of our CPG data is complicated by the presence of comparatively fast radiative and nonradiative decay channels for the singlet exciton, which compete with the field-induced dissociation. In order to provide a clear picture of the observed mechanism and disentangle it from the singlet exciton decay dynamics, we define the following phenomenological time-dependent parameter ... 

The exponent Up in Eq. (9.2) was found to be 0.65 for our samples [31 ]. With this value we attempted to model the experimental curve in Figure 9-17 by Eq. (9.8). We obtained 0.12 and 0.37 eV for the energies W, and W2, respectively. These numbers mean that the 0.12 eV process reaches the magnitude of the temperature-independent decay rale, E, at 170 K, while the 0.37 eV process reaches this level at 200 K and becomes the dominant decay channel above 220 K (see Fig. 9-17). 

From the identical shape and position of the absorption spectra (not shown) in chloroform and polysulfone we conclude that the distribution of geometries of the Ooct-OPV5-CN molecules is the same in both situations. In polysulfone, the non-radiative decay channel is effectively inhibited and a normal single-exponen-... 

Non-Radiative Decay Channels - 1064 nm Excitation. We turn now to a comparison of the observed fluorescence photon yield defined by Equation 1 and the expected fluorescence quantum yield of the 4550 cm 1 state which indicates that several non-radiative decay channels may be open following 1064 nm excitation of PuF6(g) The following relationship between... 

Decay channels and rate, nonradia-tive, PuF6(g) fluorescence... 

Deactivation of an excited state can occur not only by the abovementioned intrinsic (first-order) decay channels, but also by interaction with other species (called quenchers ) following second-order kinetics. The two most important types of interactions are those leading to energy [Eq. (5)] or electron transfer [Eqs. (6) and (7)] ( A and stand for excited molecules) [1] ... 

Yannouleas, C. and Landman, U. (2000) Decay channels and appearance sizes of doubly anionic gold and silver dusters. Physical Review B - Condensed Matter, 61, R10587-R10589. 

Zgierski MZ, Patchkovskii S, Lim EC (2005) Ab initio study of a biradical radiationless decay channel of die lowest excited electronic state of cytosine and its derivatives. J Chem Phys 123 081101... 

Zgierski MZ, Patchkovskii S, Fujiwarab T, Lim EC (2007) The role of out-of-plane deformations in subpicosecond internal conversion of photoexcited purine bases absence of the ultrafast decay channel in propanodeoxyguanosine. Chem Phys Lett 440 145-149... 

It has been calculated that the decay rate of "Tc inside a star is dramatically enhanced because of /1-decay channels (Fig. 7) from thermally populated photo-excited states at high temperature [38]. The calculation was based on a simple shell model, taking into account both continum and bound state /1-decays. The... 

Fig. 7. Thermally populated / -decay channels from "Tc to "Ru [38], Relevant proton(n) and neutron(v) shells are shown as compartments filled with nucleons (x)...

UE provides an important potential advantage beyond small size. The excited states in Si-based electronics decay by phonons, and thus a huge heat dissipation problem faces nanoscale inorganic electronics at DR = 3 nm. In contrast, UE devices may be able to decay from their excited states by photon emission [15]. If the photon decay channel can be maximized, UE devices will have a great heat advantage over inorganic ones. 

The work on muonium in Si is distinguished from that on other semiconductors in several respects. Not only was Si the first semiconductor studied, and it is the best understood semiconductor from a muonium point of view, but the importance of hydrogen and hydrogen complexes in Si, to which the muonium studies are relevant, is greatest. Much of the early work on Si predates the new spectroscopic methods described in the previous section. Since most of this early work, along with muon-decay channeling, has been reviewed by Patterson (1988), only the essential points will be included here to put into context the more recent spectroscopic developments. 

When there are only two possible decay channels for the excited state of the compound nucleus, i.e. T = Va + Vh, two simple limiting cases arise ... 

Another well-defined configuration of the classical three body Coulomb problem with unambiguous quantum correspondence is the collinear antisymmetric stretch configuration, where the electrons are located on opposite sides of the nucleus. In contrast to the frozen planet orbit, the antisymmetric stretch is unstable in the axial direction (G.S. Ezra et.al., 1991 P. Schlagheck et.al., 2003), with the two electrons colliding with the nucleus in a perfectly alternating way (Fig. 3 (left)). Hence, already the one dimensional treatment accounts for the dominant classical decay channel of this configuration. As for the frozen planet, there are doubly excited states of helium associated to the periodic orbit of the ASC as illustrated in Fig. 3 (left). 

Abstract. The —> um° decay is studied using the method of phenomenological chiral Lagrangians. Obtained in the framework of this method the expression of weak hadronic currents between vector and pseudoscalar mesons has been checked and it is shown that this decay channel proceeds only due to the — p - mixing diagram. 

Here, we consider the (ft —> unr° decay by the method of phenomenological chiral Lagrangians(PCL s)(Weinberg,1967). Studies of this decay channel is of interest in this model for the following reasons First, this decay channel is a unique laboratory for verification of weak hadron currents between pseudoscalar and vector meson states which was obtained earlier (Nasriddinov, 1998) within the formalism of phenomenological chiral Lagrangians... 

According to the method of phenomenological chiral Lagrangians (PCL s), this decay channel would originate via the intermediate D° — meson state (FIG. 2). In this case the weak interaction Lagrangian between (f) and D° mesons has the form given (Kalinovsky,1988) as... 

The structure constants of the SU(3) group responsible for this transition are equal to zero /391 = /3i0i = /39s = /3108 = 0. It should be noted that the diagrams 2 and 3 do not contribute to the partial width of the 0 — con0 decay channel which is obvious also due to the hadronic flavor conservation principle. According to the expression (2),also the anomalous diagram (FIG.4.) does not contribute to the partial width of the 0 —> W7T° decay because... 

Finally the diagram with the intermediate oj meson (FIG. 5) does not contribute to the partial width of this decay channel also because of these structure constants. 

It was shown, that this decay channel was suppressed with respect to the t —> 7r-7r°zzr decay by a factor 10-4. Therefore, it is natural that the (j) — unr° decay is strongly suppressed because of (f) — p and to — p mixings. 

The second and perhaps most probable explanation is damping and broadening of the resonance, due to size dependent, single electron 5d- 6p,6s interband transitions. Their explanation is that the discrete level structure of the Au 55 cluster acts as an effective decay channel. In reducing the plasmon lifetime, it would also strongly increase the bandwidth of the resonance, washing out the resonance peak. 

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