  We show how the recently proposed CFT for a bilayer Quantum Hall system at
filling nu=m/pm+2, the Twisted Model (TM), is equivalent to the system of two
massless scalar bosons with a magnetic boundary interaction as introduced in
Nucl. Phys. B443 (1995) 444, at the so called magic points. We are then able to
describe, within such a framework, the dissipative quantum mechanics of a
particle confined to a plane and subject to an external magnetic field normal
to it. Such an analogy is further developed in terms of the TM boundary states,
by describing the interaction between an impurity with a Hall system.
