Off-diagonal helicity density matrix elements for vector mesons produced in polarized e+e- processes

TL;DR

This paper investigates the off-diagonal helicity density matrix elements of vector mesons produced in polarized electron-positron annihilations, providing new predictions that test the Standard Model through quark-antiquark interactions.

Contribution

It introduces new theoretical predictions for the helicity density matrix element rho_{1,-1} of vector mesons at large x_E and small p_T in polarized e+e- processes, extending previous experimental findings.

Findings

Confirmed non-zero off-diagonal rho_{1,-1} elements in experimental data.

Provided new predictions for rho_{1,-1} at specific kinematic conditions.

Highlighted the dependence of results on elementary quark-antiquark dynamics.

Abstract

Final state quark-antiquark interactions give origin to non zero values of the off-diagonal element rho_{1,-1} of the helicity density matrix of vector mesons produced in e+e- annihilations, as confirmed by recent OPAL data on Phi, D^* and K^*'s. New predictions are given for rho_{1,-1} of several mesons produced at large x_E and small p_T -- i.e. collinear with the parent jet -- in the annihilation of polarized e+ and e-; the results depend strongly on the elementary dynamics and allow further non trivial tests of the Standard Model.