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

M. Anselmino; M. Bertini; F. Caruso; F. Murgia; P. Quintairos

doi:doi:10.1007/s100529900200

2020 Impact factor 4.590

Particles and Fields

Eur. Phys. J. C 11, 529-537
DOI 10.1007/s100529900200

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

M. Anselmino¹ - M. Bertini² - F. Caruso^3,4 - F. Murgia⁵ - P. Quintairos⁶

¹ Dipartimento di Fisica Teorica, Università di Torino and INFN, Sezione di Torino, Via P. Giuria 1, 10125 Torino, Italy
² Theoretical Physics, Lund University, Sölvegatan 14a, 223 62 Lund, Sweden
³ Centro Brasileiro de Pesquisas Físicas, R. Dr. Xavier Sigaud 150, 22290-180 Rio de Janeiro, Brazil
⁴ Instituto de Física da UERJ, Rua São Francisco Xavier 524, 20559-900 Rio de Janeiro, Brazil
⁵ INFN, Sezione di Cagliari and Dipartimento di Fisica, Università di Cagliari, C.P. 170, 09042 Monserrato (CA), Italy
⁶ Instituto de Física Teórica - UNESP, Rua Pamplona 145, 01405-900 São Paulo, Brazil

Received: 2 April 1999 / Revised version: 2 July 1999 / Published online: 22 October 1999

Abstract
Final-state $q\bar q$ interactions give origin to nonzero values of the off-diagonal element $\rho_{1,-1}$ of the helicity density matrix of vector mesons produced in e⁺ e^- annihilations, as has been confirmed by recent OPAL data on $\phi$ , D^*, and K^*. New predictions are given for $\rho_{1,-1}$ of several mesons produced at large x_/IE and small p/IT - 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 nontrivial tests of the standard model.