Get the SM parameters at the EW scale, using an estimate `C_out`
        of the Wilson coefficients at that scale, and run them to the
        input scale.

def _run_sm_scale_in(self, C_out, scale_sm=91.1876):
        """Get the SM parameters at the EW scale, using an estimate `C_out`
        of the Wilson coefficients at that scale, and run them to the
        input scale."""
        # initialize an empty SMEFT instance
        smeft_sm = SMEFT()
        C_in_sm = beta.C_array2dict(np.zeros(9999))
        # set the SM parameters to the values obtained from smpar.smeftpar
        C_SM = smpar.smeftpar(scale_sm, self.scale_high, C_out, basis='Warsaw')
        C_SM = {k: v for k, v in C_SM.items() if k in definitions.SM_keys}
        # set the Wilson coefficients at the EW scale to C_out
        C_in_sm.update(C_out)
        C_in_sm.update(C_SM)
        smeft_sm.set_initial(C_in_sm, scale_sm, scale_high=self.scale_high)
        # run up (with 1% relative precision, ignore running of Wilson coefficients)
        C_SM_high = smeft_sm.rgevolve(self.scale_in, newphys=False, rtol=0.01, atol=1)
        return {k: v for k, v in C_SM_high.items() if k in definitions.SM_keys}