Relative rho-omega production phase

The relative $\rho-\omega$ production phase is studied by looking at the interference effects in the dimuon decay mode of the photoproduced $\rho$ and $\omega$ mesons. This is the first measurement of the interference effect using dimuons. The data from the photoproduction experiment FOCUS at Fermi National Accelerator Laboratory (Fermilab) are used for this measurement.