Collisionless relaxation of a disequilibrated current sheet and implications for bifurcated structures

Abstract Current sheets are ubiquitous plasma structures that play the crucial role of being energy sources for various magnetic phenomena. Although a plethora current sheet equilibrium solutions have been found, collisionless process through which disequilibrated relaxes or equilibrates remains largely unknown. Here we show, analyses phase-space distributions single-particle orbit classes and particle-in-cell simulations, transitions among responsible this process. Bifurcated sheets, readily observed in geospace but whose origins remain controversial, shown to naturally arise from equilibration thus likely be underlying phenomena; comparisons spacecraft observations simulations support fact. The bearing result on previous explanations bifurcated is also discussed.