Confinement of bosonic and spinning particles in braneworlds

Abstract

In this paper the confinement of bosonic and spinning test particles in smooth Randall-Sundrum models is studied. For this, we show the possibility of finding an effective potential that describes the motion of the particle over the extra dimension. For the bosonic case, it is a known fact that free test particles can be located neither on thin nor on thick branes. Recently, a coupling to a scalar field has been used to localize a limited range of masses. Up to now, no trapped test particles of any mass over the brane were found. In order to solve this, it is shown that a coupling with the dilaton may trap particles of any mass. Next, the spinning particle is analyzed. The spin variables, , introduced an interaction with the Riemann curvature tensor. It introduced a correction to the effective potential. By analyzing it, it was found that the spinning particle may be localized at a different position from the one of the brane. It is also shown that a spinning particle over the brane may escape to infinity. Therefore, it is concluded that free bosonic and spinning particles are not trapped in the brane.