Leptophobic Z' in Heterotic-String Derived Models

Understand

The CDF collaboration's recent observation of an excess of events in the Wjj channel may be attributed to a new Abelian vector boson with suppressed couplings to leptons.

• While D0 finds no evidence of an excess, the CDF data provide an opportunity to revisit an old result on leptophobic Z' in heterotic-string derived models.
• We re-examine the conditions for the existence of a leptophobic U(1) symmetry, which arises from a combination of the U(1)_{B-L} symmetry and the horizontal flavour symmetries, to form a universal U(1) symmetry.
• While the conditions for the existence of a leptophobic combination are not generic, we show that the left-right symmetric free fermionic heterotic-string models also admit a leptophobic combination.