  We present a measurement of two-dimensional (2D) redshift-space power
spectrum for the Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 11
CMASS galaxies in the North Galactic Cap (NGC) based on the method developed by
Jing & Borner (2001). In this method, we first measure the 2D redshift-space
correlation function for the CMASS galaxies, and obtain the 2D power spectrum
based on Fourier Transform of the correlation function. The method is tested
with an N-body mock galaxy catalog, which demonstrates that the method can
yield an accurate and unbiased measurement of the redshift-space power spectrum
given the input 2D correlation function is correct. Compared with previous
measurements in literature that are usually based on direct Fourier Transform
in redshift space, our method has the advantages that the window function and
shot-noise are fully corrected. In fact, our 2D power spectrum, by its
construction, can accurately reproduce the 2D correlation function, and in the
meanwhile can reproduce, for example, the 2D power spectrum of Beutler et al.
(2014) accurately if ours is convolved with the window function they provided.
Thus, our measurement can facilitate a direct comparison with the theoretical
predictions. With this accurate measurement of the 2D power spectrum, we then
develop a method to measure the structure growth rate, by separating the
anisotropic redshift-space power spectrum from the isotropic real-space power
spectrum. We have also carefully corrected for the nonlinearities in the
mapping from real space to redshift space, according to the theoretical model
of Zhang et al. (2013). Finally, we obtain f(zeff)sigma_8(zeff)=0.438\pm0.037
at the effective redshift zeff=0.57, where f(zeff) is the linear growth rate at
redshift zeff. The result is useful for constraining cosmological parameters.
The measurements of 2D power spectrum will be released soon.
