Search for heavy resonances decaying to <math display='"inline"'> <mrow> <mi>Z</mi> <mo stretchy='"false"'>(</mo> <mi>ν</mi> <mover accent='"true"'> <mrow> <mi>ν</mi> </mrow> <mrow> <mo stretchy='"false"'>¯</mo> </mrow> </mover> </mrow></math>