Constraints on the $U(1{)}_L$ gauge boson in a wide mass range

Abstract

There is a growing interest for the search of new light gauge bosons. The small mass of a new boson can turn various kinds of low-energy experiments to a new discovery machine, depending on their couplings to the standard model particles. It is important to understand the properties of each type of gauge boson and their current constraints for a given mass. While the dark photon (which couples to the electric charges) and the $U(1{)}_{B-L}$ gauge boson have been well studied in an extensive mass range, the $U(1{)}_L$ gauge boson has not been fully investigated yet. We consider the gauge boson of the $U(1{)}_L$ in a wide mass range $m_{Z^{\prime }}\approx 0-10^{12}\text{ev}$ and investigate the constraints on its coupling from various experiments, discussing the similarities and differences from the dark photon and the $U(1{)}_{B-L}$ gauge boson.

Comments: 11 pages, 9 figures