Cross-power spectrum measured from four DESI-LIS tomographic bins. The green solid line is the theoretical power spectrum computed following our best-fit estimates of parameters b and A using the modified Lorentzian fit to the error distribution. The orange dashed line is the theoretical power spectrum corresponding to the sum of Gaussians fit to the error distribution. The standard error bars are computed from the covariance matrix used in the likelihood function, i.e. Eq. (18).