# XXVII International Workshop on Deep Inelastic Scattering and Related Subjects

Apr 8 – 12, 2019
Turin
Europe/Rome timezone

## Frame-independent angular distributions as density matrix invariants

Apr 10, 2019, 9:55 AM
17m
Rettorato - Aula Principi d'Acaja

### Rettorato - Aula Principi d'Acaja

via Verdi, 8 Turin
Parallel Session Talk WG6: Spin and 3D structure

### Speakers

Prof. Oleg Teryaev (JINR)Ms Margarita Gavrilova (JINR)

### Description

The dilepton angular distribution in vector particle decays can be described through a set of five SO(3) rotational-invariant observables. These observables are derived as invariants of the spacial part of the hadronic tensor (density matrix) expressed in terms of angular coefficients. The restrictions on the invariants following from the positivity of the hadronic tensor are obtained. Special cases of SO(2) rotations are considered. Calculation of invariants for available data on Z and J/{\psi} decays is performed.

### Presentation materials

 teryaevwg6.pdf teryaevwg6.pdf teryaevwg6.pptx