  We consider tunneling of spinless electrons from a single channel emitter
into an empty collector through an interacting resonant level of the quantum
dot (QD). When all Coulomb screening of sudden charge variations of the dot
during the tunneling is realized by the emitter channel, the system is mapped
onto an exactly solvable model of a dissipative qubit. The qubit density matrix
evolution is described with a generalized Bloch equation which permits us to
count the tunneling electrons and find the charge transfer statistics. The two
generating functions of the counting statistics of the charge transferred
during the QD evolutions form its stationary and empty state have been
expressed through each other. It is used to calculate the spectrum of the
steady current noise and demonstrate occurrence of the bifurcation of its
single zero-frequency minimum into two finite-frequency dips due to the qubit
coherent dynamics.
