The CDF dijet excess and Z'_{cs} coupled to the second generation quarks

Understand

Recently the CDF collaboration has reported the excess in the dijet invariant-mass distribution of the Wjj events, corresponding to a significance of 3.2 standard deviations.

• Considering the lack of similar excesses in the $\gamma jj$ and $Z jj$ events yet, we propose a new Z' model: Z' couples only to the second generation quarks.
• Single production of $\zsc$ as well as associated production with $W,\gamma, Z$ are mainly from the sea quarks.
• Only $W Z'$ production has additional contribution from one valence quark and one sea quark, which is allowed by CKM mixing.