Testing Cpt Symmetry with Cmb Measurements: Update after Wmap5

In this paper we update our previous result on the test of the CPT symmetry with Cosmic Microwave Background (CMB) measurements. A CPT violating interaction in the photon sector Lcs ∼ pμAν F̃ gives rise to a rotation of the polarization vectors of the propagating CMB photons. Recently the WMAP group used the newly released polarization data of WMAP5 to measure this rotation angle ∆α and obtained ∆α = −1.7±2.1 deg (1σ). In their analysis, however the BOOMERanG 2003 data is not included. In this paper we revisit this issue by combining the full data of WMAP5 and BOOMERanG 2003 angular power spectra for the measurement of this rotation angle ∆α and find that ∆α = −2.6± 1.9 deg at a 68% confidence level. Subject headings: Cosmology: theory − (Cosmology:) cosmic microwave background − (Cosmology:) cosmological parameters