Probing neutral triple gauge couplings with Z*Y (VVY) production at hadron colliders

We study probes of neutral triple gauge couplings (nTGCs) via Z*Yproduction with off-shell decays Z*-> VV at the LHC and the projected pp (100 TeV) colliders, including both CP-conserving (CPC) and CP-violating (CPV) couplings. We present the dimension-8 Standard Model effective field theory (SMEFT) operators contributing to nTGCs and derive the correct form factor formulation for the doubly off-shell vertices Z*V-Y* (V 1/4 Z,Y) by matching them with the dimension-8 SMEFT operators. We include new contributions enhanced by the large off-shell momentum of Z*, beyond those of the conventional Z.V* vertices with on-shell Z.. We analyze the sensitivity reaches for probing the CPC=CPV nTGC form factors and the new physics scales of the dimension-8 nTGC operators at the LHC and future 100 TeV pp colliders. We compare our new predictions with the existing LHC measurements of CPC nTGCs in the..<overline>. channel and demonstrate the importance of our new method.