1208.5288 (Kenji Toma et al.)

Strict Limit on CPT Violation from Polarization of Gamma-Ray Burst    [PDF]

Kenji Toma, Shinji Mukohyama, Daisuke Yonetoku, Toshio Murakami, Shuichi Gunji, Tatehiro Mihara, Yoshiyuki Morihara, Tomonori Sakashita, Takuya Takahashi, Yudai Wakashima, Hajime Yonemochi, Noriyuki Toukairin

We report the strictest observational verification of CPT invariance in the photon sector, as a result of gamma-ray polarization measurement of a distant gamma-ray burst (GRB), which is a brightest stellar-size explosion in the universe. We detected the gamma-ray polarization of GRB 110721A with high significance, and its redshift was determined as z=0.382. For the Lorentz- and CPT-violating dispersion relation E_{\pm}^2=p^2 \pm 2\xi p^3/M_{Pl}, where \pm denotes different circular polarization states of the photon, the parameter \xi is constrained as |\xi|View original: http://arxiv.org/abs/1208.5288