Laboratory-frame tests of quantum entanglement in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>H</mml:mi><mml:mo stretchy="false">→</mml:mo><mml:mi>W</mml:mi><mml:mi>W</mml:mi></mml:math>

Quantum entanglement between the two $W$ bosons resulting from decay of a Higgs boson may be investigated in dilepton channel $H\ensuremath{\rightarrow}WW\ensuremath{\rightarrow}\ensuremath{\ell}\ensuremath{\nu}\ensuremath{\ell}\ensuremath{\nu}$ using laboratory-frame observables that only involve charged leptons $\ensuremath{\ell}=e$, $\ensuremath{\mu}$. The invariant mass distribution, already measured by ATLAS and CMS Collaborations at LHC, can used to observe quantum $WW$ pair with statistical sensitivity $7\ensuremath{\sigma}$ run 2 data, $6\ensuremath{\sigma}$ when including theoretical systematics. As by-product, relation rest frame (four-dimensional) angular distributions, $H\ensuremath{\rightarrow}WW$ amplitudes, spin correlation coefficients, is written down.