  In conventional superconductors, phonons glue two electrons with opposite
spins to form Cooper pairs and condensation of these pairs leads to the
superconductivity. Identifying the underlying mechanism of the high temperature
superconductivity in cuprates is among the most important problems in physics.
Even quarter of a century after the first report of high temperature
superconductor by Bednorz and Muller in 1986, there is still no general
consensus on the pairing mechanism of superconductivity in these materials. So
far, many theories have been developed to explain the exotic properties of
cuprates, but they can explain only a limited number of experiments. In this
article, we present a new pairing mechanism that incorporates both strong
correlation and phonon mediated interaction on an equal footing to produce
superconductivity. In this framework, strong correlation and anti-ferromagnetic
interaction between electrons, create RVB pairs and phonons provide the phase
coherence between these RVB pairs. Both of these are required in this approach
to obtain the superconductivity. This approach resolves three limitations of
the U(1) slave boson method. We achieve a better estimation of $T_c$, we only
predict $\frac{h}{2ec}$ vortices and the linear $T$ coefficient of the
superfluid is not sensitive to the doping. This formalism provides a framework
that connects Anderson's idea of preformed Cooper pairs and phonon based
theories.
