in high-energy photon interactions with a nucleus A, as recently suggested in [7] (slide 23). Of course, muon-pair production by this process is suppressed relative to electron-positron pair production by the ratio (me/mμ) 2 ≈ 1/40, 000, so there is an issue of the efficiency of muon production via reaction (1). The Bethe-Heitler process (1) is further suppressed near threshold, so it would be ...

The dominant emission from bare strange stars is thought to be electron-positron pairs, produced through spontaneous pair creation (SPC) in a surface layer of electrons tied to the star by a superstrong electric field. The positrons escape freely, but the electrons are directed towards the star and quickly fill all available states, such that their degeneracy suppresses further SPC. An electron...

We show that linearly polarized gluons inside unpolarized hadrons can be directly probed in jet or heavy quark pair production in electron-hadron collisions. We discuss the simplest cos2ϕ asymmetries and estimate their maximal value, concluding that measurements of the unknown linearly polarized gluon distribution in the proton should be feasible in future Electron-Ion Collider or Large Hadron ...

Abstract Ion-pair (IP) states are the superexcited of neutral molecule that dissociate as a pair positive and negative ions. These generally present near ionization continuum molecule. IP can be accessed by using photoexcitation or electron collision technique. Different techniques widely used over years to study threshold (threshold production spectroscopy) dynamics (IP imaging states. However...

In the collision of two heavy ions, strong repulsion coming from Coulomb field is enough to produce e+e− pair(s) vacuum fluctuations. The energy provided by kinetic ions and interaction at production point. If, for instance, electron located center mass (C.M.) moving along z-axis, positron a distance x electron, can be accelerated towards each other since barrier lowered presence electron. This...

We illustrate the use of effective theory techniques to describe processes involving unstable particles close to resonance. First, we present the main ideas in the context of a scalar resonance in an Abelian gauge-Yukawa model. We then outline the necessary modifications to describe W-pair production close to threshold in electron-positron collisions.