Probe noncommutative space-time scale using γγ→Z at ILC

In the standard model production of on-shell Z boson at a photon collider (or Z decays into γγ) is strictly forbidden by angular momentum conservation and Bose statistics (the Yang's theorem). In the standard model with noncommutative space-time this process can occur. Therefore this process provides an important probe for the noncommutative space-time. The γγ collision at the ILC by laser backscattering of the electron and positron beams offers an ideal place to carry out such a study. Assuming an integrated luminosity of 500 fb−1, we show that the constraint which can be achieved on Γ(Z→γγ) is three to four orders of magnitude better than the current bound of 5.2×10−5GeV. The noncommutative scale can be probed up to a few TeVs.