Search for resonant pair production of Higgs bosons in the <math display='"inline"'> <mi>b</mi> <mover accent='"true"'> <mi>b</mi> <mo stretchy='"false"'>¯</mo> </mover> <mi>b</mi> <mover accent='"true"'> <mi>b</mi> <mo stretchy='"false"'>¯</mo> </mover> <</math>