Although double electron ($\\beta^-\\beta^-$)\ndecay is the most promising mode, in very recent years interest in double\npositron ($\\beta^+\\beta^+$) decay, positron emitting electron capture\n($EC\\beta^+$), and double electron capture ($ECEC$) has been renewed. We\npresent...
Neutrinoless double-β decay is of fundamental importance for determining the neutrino mass. Although double electron decay is the most promising mode, in very recent years interest in double positron decay, positron emitting electron capture, and double electron capture has been renewed. We present ...
A new measurement has been made of the electron capture to positron branching ratio in the decay of Na to the 1.27 MeV level in Ne. The value of 0.1077 +-0.0006 obtained is about 3% larger than other precise values and is compared with recent theoretical estimates. (author)...
The charge is positive and the absolute value is equal to that of the electron (1.602176565(35)×10−19C). Positrons are emitted from the β+-decay of radio isotopes such as 22Na and from pair creation of γ-rays. When a positron encounters matter, its likely fate is that it will ...
The hydrogen atom consists of one proton and one electron. 3 Positron A positron is created in high-energy processes like beta-plus decay. In some radioactive decays, a nucleus emits a positron. 3 Proton A proton is essential for the formation of elements. Without protons, the variety of ...
Electron-deficient, -neutral or -rich [18F]fluoroarenes were successfully prepared via this method, including [18F]FDAA110676 (a radioligand for translocator protein), obtained in 46% RCC, and 6-[18F]FBT76 (a radioligand for β-amyloid), obtained in 41% RCY (decay-corrected) with a molar...
where a nucleus X with charge number Z and atomic number A decays within its lifetime of τA,X to another nucleus Y with reduced charge number Z−1 but same atomic number by the emission of a e+ and an electron-neutrino νe. For most nuclei, this is not the sole decay branch so...
The positron-electron pair annihilation in two photons is known for its numerous applications using PET scanners. The decay of Positronium (Ps) from a standard sealed source in more than two photons is less likely but can be observed with a relatively simple setup. The main goal of this ...
There is presently a discrepancy between the theoretical and experimental determinations of the purely quantum electrodynamic decay rate for orthopositronium. This Letter presents the first exact calculation of any contribution to the decay rate of orthopositronium to order ..cap alpha../sup 7/.关键...
The process of atomic shell ionization during the annihilation of a positron, emitted at β- decay with K-electron of daughter's atom, is considered. The ratio of probabilities of these processes to the probability of ordinary β-decay is found. It excitation of atomic shell at the positron ...