Retraction: Spontaneous decay in cold dense atomic systems: caloric effect and spectrum of emitted light

2016 ◽  
Vol 94 (7) ◽  
pp. 704-704
Author(s):  
Oleg Prepelita
2016 ◽  
Vol 94 (7) ◽  
pp. 1-12
Author(s):  
Oleg Prepelita

We discuss collision-induced spontaneous decay in a system of cold atoms and caloric effect manifesting in the heating of the atomic system during spontaneous decay. It is shown that the caloric effect is caused by inelastic atom–atom collisions accompanied by the spontaneous emission of photons. Because of the imbalance between the rate of emission of the photons with the frequency higher and lower than the atomic transition frequency, the atomic system, under some conditions, is heated up. The value of the critical temperature is found, which separates the regions where the collision-induced spontaneous decay is exothermic and endothermic.


Author(s):  
Oleg Prepelita

We discuss the spontaneous decay in a system of cold identical two-level atoms when, due to the strong dipole-dipole interaction, the collision-induced spontaneous decay plays the leading role in the process. We show that the time profile of the spontaneous transition is essentially non-exponential. Also, we argue that at a low initial temperature of the atomic system the spontaneous decay is accompanied by a strong heating caused by the inelastic atom-atom collisions. We show that the spontaneous emission spectrum is asymmetric. In addition, the width of the emission spectrum is a function of time. While atoms decay the emission spectrum becomes broader. The spectrum’s asymmetry and the atomic system’s heating have the same physical origin coming from the peculiarities of the atoms distribution function.


1962 ◽  
Vol 41 (4) ◽  
pp. 619-624 ◽  
Author(s):  
Björn Tengroth ◽  
Uno Zackrisson

ABSTRACT The general change in the connective tissues which occurs in animals with experimentally produced exophthalmos, consists in an increase in the amount of hyaluronic acid, which binds the water in the connective tissue. Many regard this process as a stimulation of the mucinous system in the connective tissues, and consider this an explanation of the phenomenon of exophthalmos. When the experimental animals are injected with thyroxine or thyroid extract, the reaction observed is opposite to that seen following the injection of the anterior lobe of the pituitary gland. In the former case, there is a reduction in the amount of hyaluronic acid and consequently a decrease in the water content in the connective tissues. In the experiments in question, Na-d-thyroxine and Na-l-thyroxine), in crystalline form, were tested for their inhibiting effect on the development of exophthalmos in experimental animals. The animals used were male albino guinea-pigs. An extract of the anterior lobe of the pituitary gland (TSH Organon)) was used to produce exophthalmos. In previous work (Tengroth 1961), it was shown, using an X-ray measuring technique, that d-thyroxine, despite its poor caloric effect, like l-thyroxine had an exophthalmos-inhibiting effect. When comparing the dose-response curves of the exophthalmos-inhibiting properties of both these optical isomers, it appears that d-thyroxine has an inhibiting effect which is significantly greater than that of l-thyroxine. The significance of this observation is discussed.


2020 ◽  
Vol 101 (5) ◽  
Author(s):  
A. S. Kuraptsev ◽  
I. M. Sokolov
Keyword(s):  

2019 ◽  
Vol 125 (1) ◽  
Author(s):  
Rajkumar Modak ◽  
M. Manivel Raja ◽  
Ananthakrishnan Srinivasan

2011 ◽  
Vol 89 (1) ◽  
pp. 103-107 ◽  
Author(s):  
J.-Ph. Karr ◽  
L. Hilico ◽  
V. I. Korobov

High resolution ro-vibrational spectroscopy of H 2+ or HD+ can lead to a significantly improved determination of the electron to proton mass ratio me/mp if the theoretical determination of transition frequencies becomes sufficiently accurate. We report on recent theoretical progress in the description of the hyperfine structure of H 2+ , as well as first steps in the evaluation of radiative corrections at order mα7. Completion of the latter calculation should allow us to reach the projected 10−10 accuracy level and open the road to mass ratio determination.


2007 ◽  
pp. 33-44
Author(s):  
N. Simonovic ◽  
M. Predojevic ◽  
V. Pankovic ◽  
P. Grujic

Highly excited atoms acquire very large dimensions and can be present only in a very rarified gas medium, such as the interstellar space. Multiply excited beryllium-like systems, when excited to large principal quantum numbers, have a radius of r ? 10 ?. We examine the semiclassical spectrum of quadruple highly excited four-electron atomic systems for the plane model of equivalent electrons. The energy of the system consists of rotational and vibrational modes within the almost circular orbit approximation, as used in a previous calculation for the triply excited three-electron systems. Here we present numerical results for the beryllium atom. The lifetimes of the semiclassical states are estimated via the corresponding Lyapunov exponents. The vibrational modes relative contribution to the energy levels rises with the degree of the Coulombic excitation. The relevance of the results is discussed both from the observational and heuristic point of view.


2010 ◽  
Author(s):  
Alan D. Bristow ◽  
Xingcan Dai ◽  
Denis Karaiskaj ◽  
Galan A. Moody ◽  
Steven T. Cundiff

2010 ◽  
Vol 51 (1) ◽  
pp. 015211 ◽  
Author(s):  
O. Costin ◽  
J. L. Lebowitz ◽  
C. Stucchio ◽  
S. Tanveer
Keyword(s):  

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