We compute the third-order correction to electromagnetic S-wave quarkonium production and annihilation rates due to the emission and absorption of an ultrasoft gluon. Our result completes the analysis of the non-relativistic quarkonium bound-state dynamics in the next-to-next-to-next-to-leading order. The impact of the ultrasoft correction on the Υ(1S) leptonic width and the top quark-antiquark...

A mathematical formalism is developed for calculating the ion polarization term in the Rutherford island width evolution equation in the presence of drift-acoustic waves. The calculation is fully nonlinear, includes both ion and electron diamagnetic effects, as well as ion compressibility, but is performed in slab geometry. Magnetic islands propagating in a certain range of phase velocities are...

Using our previous approach to electromagnetic emission during tunneling, an explicit , essentially classical, formula describing the bremsstrahlung spectrum in α decay is derived. The role of tunneling motion in photon emission is discussed. The shape of the spectrum is a universal function of the ratio E γ /E 0 , where E γ is the photon energy and E 0 is a characteristic energy depending only...

Two novel sources of variable frequency microwave energy with increased efficiency are described in this paper: a backward wave oscillator (BWO) with auto modulation of electron emission and a two-section BWO, which second section operates in the traveling wave tube (TWT) mode. In the first case, the BWO output is connected through a section of a slow-wave structure to the control electrode of ...

electromagnetic waves can damage sex organs and cause hormonal disorders, and garlic isknown to reduce risk factors for various diseases. the aim of this study was to investigate theprobable effects of mobile phone radiation and the consumption of garlic on testosterone levelsand testicular changes. five groups of rats were used: control, sham (exposed to 900 mhzwavelength), experimental group ...

It is well known that electrons passing through a magnetic undulator emit partially coherent radiation: `Undulator Synchrotron Radiationa. Radiation from electrons, entering the undulator at random, adds incoherently. If the electron beam is periodically modulated (bunched) to pulses shorter than the radiation wavelength, electrons radiate in phase with each other, resulting in super-radiant em...

To address the important issue of how kinetic energy of collimated blast waves is converted into radiation, Pohl & Schlickeiser (2000) have recently investigated the relativistic two-stream instability of electromagnetic turbulence. They have shown that swept-up matter is quickly isotropized in the blast wave, which provides relativistic particles and, as a result, radiation. Here we present ne...

We use the cyclotron-maser theory to explain the core emission from the magnetosphere of pulsars. As a kind of direct and efficient maser type of emission, it can give rise to escaping radiation with extremely high brightness temperature and narrow angle with respect to the magnetic axis. We find that the growth rates and real frequencies of the O-mode electromagnetic wave propagating parallel ...

We interpret gamma ray bursts as relativistic, electromagnetic explosions. Specifically, we propose that they are created when a rotating, relativistic, stellar-mass progenitor loses much of its rotational energy in the form of a Poynting flux during an active period lasting ∼ 100 s. Initially, a non-spherically symmetric, electromagnetically-dominated bubble expands non-relativistically inside...