It is well known that positrons can live long enough to form complexes with atoms. The theoretical study of these complexes is important to interpret experimental data from both positron scattering by atoms and molecules and positron annihilation spectroscopy. There are typically two different kinds of positron complexes. In one of them a positron attaches to a neutral or ionic atom or molecule...

An update is presented of the analysis of the H1 experiment at the HERA electron/positron-proton collider including the luminosity taken in 1997. Topics covered are: Status of the excess in deep-inelastic positron-proton scattering at very high Q 2 reported earlier and new results on neutral and charged current cross-sections at high Q 2 , limits on the couplings of lep-toquarks of the 1st and ...

The Compton positron source of a future linear collider must obtain the target bunch population by accumulating a large number of positron packets, arriving either in a number of bursts from a ‘Compton ring’, with intermediate damping of the scattering electron beam, or quasicontinually from a ‘Compton energy recovery linac’. We present simulation results for the longitudinal stacking of Compto...

We have used a low-energy positron beam to identify and quantify the dominant vacancy defects in InN layers grown on Al2O3 by molecular beam epitaxy. By applying both continuous and pulsed positron beams, we can show that In vacancies are formed during the crystal growth. Their concentration decreases from B5 10 to below 10 cm 3 with increasing layer thickness (120–800 nm). The In vacancy conce...

We present the contributions from all types of one-loop corrections to the scattering amplitude for the pair production of polarized charginos or neutralinos from polarized electron-positron annihilation. The contributions are classified in terms of “prototypes” distinguished by the number of particles inside the loops and their spins. The results are quoted in terms of the Veltman-Passarino fu...

In the previous work, "Spin correlations in elastic $e^+ e^-$ scattering QED" (Yongram, 2018), spin for entangled electrons and positrons as emergent particles of electron-positron (also known Bhabha scattering) were calculated at tree level QED. When trying to reproduce author's we have found different results. this show calculation fully (initial final polarized states) partially (just probab...