scholarly journals Evolution of atom entropy in a moving cascade three-level atom in a two-photon process

2008 ◽  
Vol 57 (4) ◽  
pp. 2205
Author(s):  
Zhang Jin-Fang ◽  
Tan Lei ◽  
Liu Li-Wei ◽  
Ding Cai-Ying
Keyword(s):  
Two Photon ◽  
Level Atom ◽  
Photon Process

ac Stark effect for a two-level atom in a squeezed vacuum via a two-photon process

1999 ◽  
Vol 7 (1) ◽  
pp. 117-121 ◽  
Author(s):  
Xun-Li Feng ◽  
Zhao-Yang Chen ◽  
Zhi-Zhan Xu
Keyword(s):  
Stark Effect ◽  
Two Photon ◽  
Squeezed Vacuum ◽  
Level Atom ◽  
Photon Process ◽  
Ac Stark Effect

Two-level atom in a squeezed vacuum with the two photon process via ac-Stark effect

2005 ◽  
Vol 26 (2) ◽  
pp. 467-479 ◽  
Author(s):  
T.M. El-Shahat ◽  
A.A. Eied ◽  
A.-S.F. Obada
Keyword(s):  
Stark Effect ◽  
Two Photon ◽  
Squeezed Vacuum ◽  
Level Atom ◽  
Photon Process ◽  
Ac Stark Effect

Two-photon emission spectrum of a two-level atom in an ideal cavity

1994 ◽  
Vol 49 (5) ◽  
pp. 4009-4015 ◽  
Author(s):  
Lin-sheng He ◽  
Xun-li Feng
Keyword(s):  
Emission Spectrum ◽  
Photon Emission ◽  
Two Photon ◽  
Level Atom

scholarly journals One Photon and Two Photon Process in Photo-Decomposition of Germanium Oxygen Deficient Centres

1998 ◽  
Vol 37 (S1) ◽  
pp. 12 ◽  
Author(s):  
L. Dong ◽  
V. N. Bagratashvili ◽  
S. I. Tsypina ◽  
Y. S. Zavorotny ◽  
A. O. Rybaltovskii ◽  
...  
Keyword(s):  
Two Photon ◽  
Photon Process ◽  
Photo Decomposition

scholarly journals ANTIBUNCHING EFFECT OF TWO PHOTON FLUORESCENT LIGHT FOR A TWO LEVEL ATOM IN A SQUEEZED VACUUM

1997 ◽  
Vol 46 (9) ◽  
pp. 1718
Author(s):  
FENG XUN-LI ◽  
HE LIN-SHENG ◽  
LIU YONG-LIANG
Keyword(s):  
Fluorescent Light ◽  
Two Photon ◽  
Squeezed Vacuum ◽  
Level Atom ◽  
Antibunching Effect

scholarly journals Recent BaBar results in light hadron spectroscopy

2019 ◽  
Vol 212 ◽  
pp. 04006
Author(s):  
Evgeny Kozyrev ◽  
Evgeny Solodov ◽  
Vladimir Druzhinin
Keyword(s):  
Center Of Mass ◽  
Mass Energy ◽  
Full Data ◽  
Data Set ◽  
Hadron Spectroscopy ◽  
Center Of Mass Energy ◽  
Two Photon ◽  
Light Hadron ◽  
Photon Process ◽  
Babar Experiment

We report the results on the channels e+e−→ π+π−π0π0π0(η), e+e−→ π+π−η. Also we present the study of the two-photon process e+e−→ e+e−η' in the double-tag mode. The results for the form factor are compared with the predictions based on pQCD and VMD. The results are obtained by using the full data set of about 470 fb−1 collected by the BABAR experiment at the PEP-II e+e−collider at a center-of-mass energy of about 10.6 GeV.

scholarly journals Hydrogen spin oscillations in a background of axions and the 21-cm brightness temperature

2020 ◽  
Author(s):  
G Lambiase ◽  
S Mohanty
Keyword(s):  
Cosmic Strings ◽  
Transition Rates ◽  
Spin Temperature ◽  
Level Atom ◽  
Spin Flip ◽  
Coherent Field ◽  
Unique Method ◽  
Photon Process ◽  
The Right ◽  
The Universe

Abstract The 21-cm line signal arising from the hyperfine interaction in hydrogen has an important role in cosmology and provides a unique method for probing of the universe prior to the star formation era. We propose that the spin flip of Hydrogen by the coherent emission/absorption of axions causes a lowering of their spin temperature and can explain the stronger than expected absorption of 21-cm light reported by the EDGES collaboration. We find the analogy of axion interaction with the two level HI with the Jaynes-Cummings model of a two level atom in a cavity and we derive the spin flip frequency in this formalism and show that the coherent oscillations frequency Ω∝1/fa in contrast with the incoherent transitions between the HI hyperfine levels where the transition rates $\propto 1/f_a^2$. The axion emission and absorption rates are equal but the spin temperature is still lowered due to different selection rules for the spin flip transitions compared to the photon process. We show that the axion process goes in the right direction for explaining the EDGES observation. For this mechanism to work we require a coherent field of relativistic axions with energy Eν peaked at the 21-cm spin-flip energy. Such a coherent background of relativistic axions can arise from the decay of cosmic strings if the decay takes place in the electroweak era.

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