Diphoton excess from hidden U(1) gauge symmetry with large kinetic mixing

Understand

We show that the 750 GeV diphoton excess can be explained by introducing vector-like quarks and hidden fermions charged under a hidden U(1) gauge symmetry, which has a relatively large coupling constant as well as a significant kinetic mixing with U(1)$_Y$.

• With the large kinetic mixing, the standard model gauge couplings unify around $10^{17}$ GeV, suggesting the grand unified theory without too rapid proton decay.
• Our scenario predicts events with a photon and missing transverse momentum, and its cross section is related to that for the diphoton excess through the kinetic mixing.
• We also discuss other possible collider signatures and cosmology, including various ways to evade constraints on exotic stable charged particles.