$d$-th AD determined by the baselines and antineutrino fluxes. The uncorrelated reactor uncertainty is $\sigma_r$ (0.8%). The parameter $\sigma_d$ (0.2%) is the uncorrelated detection uncertainty. The parameter $\sigma_{B}$ ($\sim0.2$%) is the quadratic sum of the background uncertainties, which are site dependent. The corresponding pull parameters are ($\alpha_r, \varepsilon_d, \eta_d$). The absolute normalization $\varepsilon$, which absorbs the detector- and reactor-related correlated uncertainties, is a free parameter determined from the fit to the data. While keeping $\varepsilon$ free, the reactor antineutrino flux is determined by the near site measurements. The model-dependent reactor flux prediction enters the fit only at secondary order.

With increased statistics, the latest Daya Bay analyses are based on rate and shape analysis. While rate deficit still dominates the $\theta_{13}$ sensitivity, the spectral information starts to contribute. To take advantage of the spectral information, an analysis with a similar $\chi^2$ expression as defined in Eq. \[eqn:chi2\] but with energy bins and relevant uncertainties is used. Additional inputs to the fit include the background shape uncertainties and energy nonlinearity model described in Sec. \[signal\]. Besides improving the precision of the $\sin^22\theta_{13}$, the effective mass splitting $\Delta m^2_{ee}$ has been measured for the first time [@DB_spectana].

Another approach in extracting the 