  We show here that many of the normal state properties of the cuprates can
result from the new charge 2e bosonic field which we have recently (Phys. Rev.
Lett. {\bf 99}, 46404 (2007) and Phys. Rev. B 77, 014512 (2008)) shown to exist
in the exact low-energy theory of a doped Mott insulator. In particular, the 1)
mid-infrared band including the non-vanishing of the restricted f-sum rule in
the Mott insulator, 2) the $T^2$ contribution to the thermal conductivity, 3)
the pseudogap, 4) the bifurcation of the electron spectrum below the chemical
potential as recently seen in angle-resolved photoemission, 5) insulating
behaviour away from half-filling, 6) the high and low-energy kinks in the
electron dispersion and 7) T-linear resistivity all derive from the charge 2e
bosonic field.
  We also calculate the inverse dielectric function and show that it possesses
a sharp quasiparticle peak and a broad particle-hole continuum. The sharp peak
is mediated by a new charge e composite excitation formed from the binding of a
charge 2e boson and a hole and represents a distinctly new prediction of this
theory. It is this feature that is responsible for dynamical part of the
spectral weight transferred across the Mott gap. We propose that electron
energy loss spectroscopy at finite momentum and frequency can be used to probe
the existence of such a sharp feature.
