Pair creation: Back reactions and damping

Abstract

We solve the quantum Vlasov equation for fermions and bosons, incorporating spontaneous pair creation in the presence of back reactions and collisions. Pair creation is initiated by an external impulse field and the source term is non-Markovian. A simultaneous solution of Maxwell's equation in the presence of feedback yields an internal current and electric field that exhibit plasma oscillations with a period pl . Allowing for collisions, these oscillations are damped on a time scale r determined by the collision frequency. Plasma oscillations cannot affect the early stages of the formation of a quark-gluon plasma unless r ӷ pl and pl ϳ1/⌳ QCD ϳ1 fm/c. ͓S0556-2821͑99͒06123-8͔

Plasma production and thermalisation in a strong field

“…; e.g., Refs. [14,15], because it is manageable and better models the conditions produced by an URHIC. Clearly, just after the impact the parton number density is small and hence the time between successive collisions is large.…”

“…is a regularising counterterm, determined via the same procedure [14] that yields the renormalised currents in Sec. II B, which ensures that the integrals involving the calculated distribution function are finite.…”

“…However, its complexity mitigates against its use in semi-quantitative, exploratory studies and hence herein we employ a simple RTA [14,15,18,19,20,21,22,23].…”

“…This phrase simply describes the fact that once the particles are produced they are accelerated and thereby generate a field that interferes with the collisional field that produced them. Plasma oscillations are then almost inevitable [16], although they can rapidly be damped if the thermalising collisions between particles are frequent [14,15,17,18,19,20,21,22,23].…”

“…Particle production by the flux tube is described by a source term and in quantum field theory that source term is non-Markovian [10,11,12,13,14,15]; i.e., essentially nonlocal in time. This feature can be important when the fields are strong.…”