Ground state positronium: Hyperfine structure and decay rates

2005 ◽  
pp. 118-145
Author(s):  
P. W. Zitzewitz
Keyword(s):  
Hyperfine Structure ◽  
Ground State ◽  
Decay Rates

Positronium and quantum electrodynamics

1982 ◽  
Vol 60 (4) ◽  
pp. 543-550 ◽  
Author(s):  
D. W. Gidley
Keyword(s):  
Fine Structure ◽  
Excited State ◽  
Hyperfine Structure ◽  
Ground State ◽  
Quantum Electrodynamics ◽  
Experimental Tests ◽  
Decay Rates ◽  
Experimental Techniques

Experimental tests of quantum electrodynamics using positronium are reviewed. These tests include measurements of the ground state hyperfine structure, excited state fine structure, and the annihilation decay rates of positronium. Emphasis is given to describing the present experimental techniques, comparing the most recent results with theory, and summarizing possible future improvements in the measurements.

Ground-State Hyperfine Structure ofDy165

1968 ◽  
Vol 165 (4) ◽  
pp. 1360-1362 ◽  
Author(s):  
Alan T. Ramsey ◽  
Sanford Stein
Keyword(s):  
Hyperfine Structure ◽  
Ground State

Hyperfine structure investigations in the4F9/2 atomic ground state of191Ir and193Ir

1973 ◽  
Vol 263 (4) ◽  
pp. 341-346 ◽  
Author(s):  
S. Büttgenbach ◽  
M. Herschel ◽  
G. Meisel ◽  
E. Schrödl ◽  
W. Witte ◽  
...  
Keyword(s):  
Hyperfine Structure ◽  
Ground State ◽  
Atomic Ground State ◽  
Structure Investigations

scholarly journals Recent results for the logarithmic Keller-Segel-Fisher/KPP System

2019 ◽  
Vol 38 (7) ◽  
pp. 37-48
Author(s):  
Yanni Zeng ◽  
Kun Zhao
Keyword(s):  
Ground State ◽  
Decay Rates ◽  
Optimal Time ◽  
Logistic Growth ◽  
Time Behavior ◽  
Long Time Behavior ◽  
Chemotaxis Model ◽  
Time Decay Rates ◽  
Long Time ◽  
Logarithmic Sensitivity

We consider a Keller-Segel type chemotaxis model with logarithmic sensitivity and logistic growth. It is a 2 by 2 system describing the interaction of cells and a chemical signal. We study Cauchy problem with finite initial data, i.e., without the commonly used smallness assumption on  initial perturbations around a constant ground state. We survey a sequence of recent results by the authors on  the existence of global-in-time solution,  long-time behavior, vanishing coefficient limit and optimal time decay rates of the solution.

Hyperfine Structure of the Ground State ofMn55

1971 ◽  
Vol 3 (4) ◽  
pp. 1220-1223 ◽  
Author(s):  
S. J. Davis ◽  
J. J. Wright ◽  
L. C. Balling
Keyword(s):  
Hyperfine Structure ◽  
Ground State

Evaluation of Luminescence Decay Measurements Probed on Pure and Doped Pt(IV) Hexahalogeno Complexes. II. Molecular Properties Obtained from Temperature Dependent Lifetime Curves

1997 ◽  
Vol 52 (5) ◽  
pp. 447-456
Author(s):  
Ingo Biertümpel ◽  
Hans-Herbert Schmidtke
Keyword(s):  
Excited States ◽  
Ground State ◽  
Energy Levels ◽  
Decay Rates ◽  
Rate Equations ◽  
Temperature Dependent ◽  
Lifetime Measurements ◽  
Thermally Activated ◽  
Ground State Energies ◽  
Higher Excited States

Abstract Lifetime measurements down to nearly liquid helium temperatures are used for determining energy levels and transition rates between excited levels and relaxations into the ground state. Energies are obtained from temperature dependent lifetimes by fitting experimental curves to model functions pertinent for thermally activated processes. Rates are calculated from solutions of rate equations. Similar parameters for pure and doped Pt(IV) hexahalogeno complexes indicate that excited levels largely belong to molecular units. Some of the rates between excited states are only somewhat larger than decay rates into the ground state, which is a consequence of the polyexponential decay measured also at low temperature (2 K). In the series of halogen complexes, the rates between spinorbit levels resulting from 3T1g increase from fluorine to bromine, although energy splittings become larger. Due to the decreasing population of higher excited states in this series, K^PtFö shows a tri-exponential, K2PtCl6 a bi-exponential and FoPtBr6 a mono-exponential decay. In the latter case the population density of higher excited states relaxes so fast that emission occurs primarily from the lowest excited Γ3(3T1g) level. Phase transitions and emission from chromophores on different sites can also be observed.

scholarly journals Two-phonon structures for beta-decay theory

2018 ◽  
Vol 194 ◽  
pp. 02008
Author(s):  
A.P. Severyukhin ◽  
N.N. Arsenyev ◽  
I.N. Borzov ◽  
R.G. Nazmitdinov ◽  
S. Åberg
Keyword(s):  
Random Matrix ◽  
Single Particle ◽  
Ground State ◽  
Matrix Theory ◽  
Decay Rates ◽  
Total Probability ◽  
Phonon Coupling ◽  
Skyrme Interaction ◽  
Β Decay ◽  
Gamow Teller

The β-decay rates of 60Ca have been studied within a microscopic model, which is based on the Skyrme interaction T45 to construct single-particle and phonon spaces. We observe a redistribution of the Gamow–Teller strength due to the phonon-phonon coupling, considered in the model. For 60Sc, the spin-parity of the ground state is found to be 1+. We predict that the half-life of 60Ca is 0.3 ms, while the total probability of the βxn emission is 6:1%. Additionally, the random matrix theory has been applied to analyze the statistical properties of the 1+ spectrum populated in the β-decay to elucidate the obtained results.

Hyperfine Structure of Tritium in the Ground State

1957 ◽  
Vol 106 (1) ◽  
pp. 87-89 ◽  
Author(s):  
A. G. Prodell ◽  
P. Kusch
Keyword(s):  
Hyperfine Structure ◽  
Ground State
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