Leptophobic $Z'$ in Models with Multiple Higgs Doublet Fields

Understand

We study the collider phenomenology of the leptophobic $Z'$ boson from an extra $U(1)'$ gauge symmetry in models with $N$-Higgs doublet fields.

• We assume that the $Z'$ boson at tree level has (i) no $Z$-$Z'$ mixing, (ii) no interaction with charged leptons, and (iii) no flavour-changing neutral current.
• Under such a setup, it is shown that in the $N=1$ case, all the $U(1)'$ charges of left-handed quark doublets and right-handed up- and down-type quarks are required to be the same, while in the $N \ge 3$ case one can take different charges for the three types of quarks.
• The $N=2$ case is not well-defined under the above three requirements.