The Production of $\Xi_{bb}$ at Photon Collider
  The inclusive production of the doubly heavy baryon $\Xi_{bb}$ is investigated at polarized and unpolar- ized photon collider. bb pair in both color triplet and sextet have been considered to transform into $\Xi_{bb}$. The results indicate that the contribution from color sextet is about 8% for $\Xi_{bb}$ production. For the ILC collision energy ranging from 91GeV to 1000GeV, the total cross section of $\Xi_{bb}$ shows a downtrend, i.e., the production of $\Xi_{bb}$ has the maximal rate at $\sqrt S = 91GeV$. Our results indicate that the initial beam polarization may be an important asset for the production of $\Xi_{bb}$. At some collision point, the production rate of $\Xi_{bb}$ can be increased about 17% with an appropriate choice of the initial beam polarization. 
Zhong-Juan Yang, Xiao-Xia Zhao (Henan Polytech. U.)
hep-ph