Radiative decay constants of the H2 Fulcher bands

1978 ◽  
Vol 69 (12) ◽  
pp. 5518-5520 ◽  
Author(s):  
Ray L. Day ◽  
Richard J. Anderson ◽  
Francis A. Sharpton
1974 ◽  
Vol 61 (11) ◽  
pp. 4740-4746 ◽  
Author(s):  
T. Oka ◽  
K. V. S. Rama Rao ◽  
J. L. Redpath ◽  
R. F. Firestone

1980 ◽  
Vol 58 (10) ◽  
pp. 1046-1050 ◽  
Author(s):  
A. K. Gupta ◽  
Sekhar Basu ◽  
K. K. Rohatgi-Mukherjee

Excited state lifetimes of anthracene-1-sulphonate, anthracene-2-sulphonate, anthracene-1,5-disulphonate, and anthracene-1,8-disulphonate have been studied by photoselection and single photon counting methods. Experimental lifetimes are compared with theoretical values. For anthracene- monosulphonates, exciplex formation with water is proposed. In the case of anthracene-1,8-disulphonate, distortion in molecular geometry is found responsible for the higher non-radiative decay constant. Summation of nonradiative decay constants, Σki, increase in the series [Formula: see text]. The sharp increase for 1,8-AS is perhaps due to distortion of the molecular geometry due to steric effect of two bulky and charged —SO3− groups on the same side of the anthracene skeleton.


1977 ◽  
Vol 66 (1) ◽  
pp. 351-354 ◽  
Author(s):  
P. J. Marcoux ◽  
L. G. Piper ◽  
D. W. Setser

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Hluf Negash ◽  
Shashank Bhatnagar

We study the radiative decay widths of vector quarkonia for the process of J/ψ(nS)→ηc(nS)γ and Υ(nS)→ηb(nS)γ (for principal quantum numbers n=1,2,3) in the framework of Bethe-Salpeter equation under the covariant instantaneous ansatz using a 4×4 form of BSE. The parameters of the framework were determined by a fit to the mass spectrum of ground states of pseudoscalar and vector quarkonia, such as ηc, ηb, J/ψ, and Υ. These input parameters so fixed were found to give good agreements with data on mass spectra of ground and excited states of pseudoscalar and vector quarkonia, leptonic decay constants of pseudoscalar and vector quarkonia, two-photon decays, and two-gluon decays of pseudoscalar quarkonia in our recent paper. With these input parameters so fixed, the radiative decay widths of ground (1S) and excited (2S,3S) states of heavy vector quarkonia (J/Ψ and Υ) are calculated and found to be in reasonable agreement with data.


2019 ◽  
Vol 204 ◽  
pp. 08006 ◽  
Author(s):  
Viktor Andreev ◽  
Vadzim Haurysh

The procedure for obtaining the radiative decay constants of pseudoscalar and vector unflavored mesons in point–form of Poincaré-invariant quantum mechanics is presented. In the course of the work the authors determine the remaining parameters from V → Pγ and P → Vγ experimental decay value, using the obtained earlier parameters of the model for light (u, d and s) quarks. As a result, the mixing angles for pseudoscalar and vector meson sector were obtained taking into account gluonium content for η – η′ meson sector.


1975 ◽  
Vol 32 (2) ◽  
pp. 328-331 ◽  
Author(s):  
C.J. Werkhoven ◽  
T. Deinum ◽  
J. Langelaar ◽  
R.P.H. Rettschnick ◽  
J.D.W. van Voorst

2019 ◽  
Vol 64 (6) ◽  
pp. 451 ◽  
Author(s):  
V. Yu. Haurysh ◽  
V. V. Andreev

The procedure for obtaining the radiative decay constants of pseudoscalar and vector unflavored mesons in the point-form of PiQM is presented. Based on the obtained earlier parameters of the model for light (u, d, s) quarks, we obtain the remaining parameters from the experiments on the V → Py and P → Vy decays. As a result, the mixing angles for pseudoscalar and vector mesons and the behavior of the V → Pℓ+ℓ− decay constant are obtained in agreement with modern experimental data.


Author(s):  
V. Yu. Haurysh ◽  
V. V. Andreev

In the framework of the relativistic quark model based on the point form of the Poincaré-invariant quantum mechanics, the parameters were fixed using the integral representations of the lepton decay constants of pseudoscalar and vector mesons containing u-, d- and s-quarks. As a result of numerical calculations using the oscillator wave function, the basic parameters of the model are obtained using the pseudoscalar density constant and current quark masses. The analysis showed that the obtained calculation results in the framework of the model and the experimental data on the lepton decays of hadrons agree well with each other. As a result, the calculation method is generalized to the case of hadronic transitions with γ-quantum emission and a subsequent calculation of the integral representations of radiative decay constants of pseudoscalar and vector mesons. The obtained values of the anomalous magnetic moments are compared with the baryon data. As a test of the model, the authors studied the behavior of the form-factors of radiative decays of vector mesons with a subsequent comparison to the modern experimental data in the q < 0.5 GeV range where the resonance effects are insignificant. As a result, self-consistent descriptions of lepton and radiative transitions were obtained within the framework of the model proposed by the authors.


1982 ◽  
Vol 60 (18) ◽  
pp. 2332-2339 ◽  
Author(s):  
Michel Belletete ◽  
Gilles Durocher

Fluorescence quantum yields [Formula: see text], theoretical first-singlet radiative decay constants (kF(t)), and first-singlet non-radiative decay constants (knr) of some benzylideneanilines (BA) dissolved in methylcyclohexane have been obtained. High values of knr are interpreted by the twisting of the molecules around the azomethine bond (C=N) in the first singlet excited state. The absorption spectra of some BA's have also been obtained in methylcyclohexane with various added amounts of polar molecules. BA's with strong electron-donor and/or strong electron-acceptor substituents in the para positions give rise to the formation of ground state complexes with small polar molecules. The stoichiometry of the complex is one BA molecule for two polar solvent molecules; when ethanol is used as a polar solvent, it is further involved in hydrogen bonding formation. The fluorescence spectra of 4-dimethylaminobenzylidene-4′-nitroaniline have been obtained in methylcyclohexane with various added amounts of polar species. The results are interpreted by the formation of exciplexes with polar compound. The Lippert–Mataga theory and the more generalized Kawski theory failed to explain the solute-solvent interactions disussed in this paper.


2011 ◽  
Vol 20 (06) ◽  
pp. 1437-1454 ◽  
Author(s):  
SHASHANK BHATNAGAR ◽  
SHI-YUAN LI ◽  
JORGE MAHECHA

We have employed the framework of Bethe–Salpeter equation under covariant instantaneous ansatz to calculate leptonic decay constants of unequal mass pseudoscalar mesons like π±, K, D, DS and B, and radiative decay constants of neutral pseudoscalar mesons like π0 and ηc into two photons. In the Dirac structure of hadronic Bethe–Salpeter wave function, the covariants are incorporated from their complete set in accordance with a recently proposed power counting rule. The contribution of both leading order and next-to-leading order Dirac covariants to decay constants are studied. The results are found to improve and hence validating the power counting rule which provides a practical means of incorporating Dirac covariants in the Bethe–Salpeter wave function for a hadron.


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