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Browsing Publicēti raksti (FMOF) / Published Articles by Author "Ferber, Ruvin"

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    Fourier-transform spectroscopy, direct-potential-fit, and electronic structure calculations on the entirely perturbed (4)1Π state of RbCs
    (American Physical Society, 2018-12-26) Klincare, Ilze; Kruzins, Artis; Tamanis, Maris; Ferber, Ruvin; Pazyuk, Elena A.; Stolyarov, Andrey V.
    We performed a high-resolution Fourier-transform spectroscopic study of the (4)1Π state of the RbCs molecule by applying two-step (4)1Π ← A1Σ+ ∼ b3Π ← X1Σ+ optical excitation followed by observation of the (4)1Π → X1Σ+ laser induced fluorescence (LIF) spectra. In many LIF progressions the collision-induced satellite rotational lines were observed thus increasing the amount of term values and allowing to estimate the Λ-doubling effect in the (4)1Π state. The Direct-Potential-Fit (DPF) of experimental term values of 777 rovibronic levels of both 85RbCs and 87RbCs isotopologues has been performed by means of the robust weighted non-linear least squares method. The PFanalysis based on adiabatic approximation and analytical Expanded Morse Oscillator potential revealed numerous regular shifts in the measured level positions. The spectroscopic studies of the (4)1Π state were supported by the electronic structure calculations including the potential energy curves of the singlet and triplet states manifold and spin-allowed transition dipole moments. The subsequent estimates of radiative lifetimes and corresponding vibronic branching ratios elucidated a dominant contribution of the (4)1Π → A ∼ b channel into the total radiative decay of the (4)1Π state. The relative intensity distributions simulated for (4)1Π → X1Σ+ LIF progressions agree well with their observed counterparts even for the profoundly shifted levels of the entirely perturbed (4)1Π state. To get an insight into the origin of the intramolecular perturbations the relevant spin-orbit and L-uncoupling electronic matrix elements were evaluated
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    A Numbers-Based Approach to a Free Particle's Spacetime
    (2020) Ferber, Ruvin
    A possibility is proposed to define the proper spacetime of a free nonzerorest- mass m_0 particle based on the connection of its lasting proper time to an open sequence of natural numbers counting de Broglie time periods (h/c^2)(m^(-1)_ 0 ) [see R. Ferber, A Missing Link: What is Behind de Broglie's" Periodic Phenomenon"?, Foundations of Physics Letters 9, 575 (1996)]. It is suggested to define a set of twodirectional intervals of the particle's proper space (proper distances) following the construction of positive and negative integers from the ordered pairs of the natural numbers, which belong to the sequence 1, 2, ..., n defining the elapsed interval of de Broglie time t_n. Corresponding to rational numbers, the ratios of proper distances to their common time interval tn are referred to as proper velocities, which are expressed by a rational fraction of c without supposing any relation to an external system of coordinates. The particle's proper reference frame appears by resolving the t_n over proper spatial and temporal coordinates, which are connected in a wave-like process. The corresponding connection in energy representation takes the form of relativistic energy-momentum relation of the respective proper quantities, which reveals the existence, besides the rest energy term m_0c^2, of the term attributed to particle's proper space that is mainly determined by large proper distances and approaches with growing tn the finite value of the order of m_0c^2.