Strict limit on CPT violation from polarization of γ-ray bursts.
We report the strictest observational verification of CPT invariance in the photon sector, as a result of γ-ray polarization measurement of distant gamma-ray bursts (GRBs), which are the brightest stellar-sized explosions in the Universe. We detected γ-ray polarization of three GRBs with high significance levels, and the source distances may be constrained by a well-known luminosity indicator for GRBs. For the Lorentz- and CPT-violating dispersion relation E(±)(2) = p(2) ± 2ξp(3)/M(Pl), where ± denotes different circular polarization states of the photon, the parameter ξ is constrained as |ξ|<O(10(-15)). Barring precise cancellation between quantum gravity effects and dark energy effects, the stringent limit on the CPT-violating effect leads to the expectation that quantum gravity presumably respects the CPT invariance.
Department of Earth and Space Science, Osaka University, Toyonaka 560-0043, Japan.
Kenji
K
Toma
Shinji
S
Mukohyama
Daisuke
D
Yonetoku
Toshio
T
Murakami
Shuichi
S
Gunji
Tatehiro
T
Mihara
Yoshiyuki
Y
Morihara
Tomonori
T
Sakashita
Takuya
T
Takahashi
Yudai
Y
Wakashima
Hajime
H
Yonemochi
Noriyuki
N
Toukairin