Rare Z Boson Decays to a Hidden Sector

Nikita Blinov, Eder Izaguirre, and Brian Shuve

Physical Review D 97 (2018) 15009


We demonstrate that rare decays of the Standard Model ( Z ) boson can be used to discover and characterize the nature of new hidden-sector particles. We propose new searches for these particles in soft, high-multiplicity leptonic final states at the Large Hadron Collider. The proposed searches are sensitive to low-mass particles produced in ( Z ) decays, and we argue that these striking signatures can shed light on the hidden-sector couplings and mechanism for mass generation.