Study of polarization in ZZ production in CMS

Polarization in diboson production serves as an important test of electroweak symmetry breaking mechanism and can be used as a tool to search for new physics effects. This is also a first step to studying longitudinal polarization in the rare process of vector boson scattering. This analysis measures polarization fractions using angular distribution of decay products in ZZ to four lepton final state produced in proton-proton collisions at centre-of-mass energy of 13 TeV using Run 2 data collected with Compact Muon Solenoid (CMS) detector of Large Hadron Collider. ZZ candidates are reconstructed using two same-flavour opposite-charge lepton pairs. We examine several kinematic variables to distinguish between the various polarization modes in ZZ events. A measurement of polarization fractions for each mode in different m4l bins will be performed. This presentation describes the current progress toward the completion of this analysis.