Constraints on gaugedB−3Lτand related theories

Lay Nam Chang, Oleg Lebedev, Will Loinaz, Tatsu Takeuchi
2001 Physical Review D, Particles and fields  
We consider extensions of the Standard Model with an extra U(1) gauge boson which couples to B-(alpha L_e + beta L_mu + gamma L_tau) with alpha + beta + gamma = 3. We show that the extra gauge boson necessarily mixes with the Z leading to potentially significant corrections to the Z-f-fbar vertex. The constraints on the size of this correction imposed by the Z-pole data from LEP and SLD are derived.
doi:10.1103/physrevd.63.074013 fatcat:ogkuqlrhrjh5nmpexudvt3tode