The Z boson spin observables as messengers of new physics

Authors :: Aguilar-Saavedra, J. A.
Bernabéu, J.
Mitsou, V. A.
Segarra, A.
Publication Year :: 2017
Abstract: We demonstrate that the 8 multipole parameters describing the spin state of the $Z$ boson are able to disentangle known $Z$ production mechanisms and signals from new physics at the LHC. They can be extracted from appropriate asymmetries in the angular distribution of lepton pairs from the $Z$ boson decay. The power of this analysis is illustrated by (i) the production of $Z$ boson plus jets; (ii) $Z$ boson plus missing transverse energy; (iii) $W$ and $Z$ bosons originating from the two-body decay of a heavy resonance.<br />Comment: LaTeX 13 pages. v2: comments and references added, journal version