1997/08/16 by K. Ackerstaff, The OPAL Collaboration, G. Alexander +99 · 1 citation
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ex
paper · pdf · doi:10.1016/s0370-2693(97)01077-0
published as Phys.Lett.B412:210-224,1997 · 19 pages, LaTeX, uses a4p.sty, pennames.sty, 4 eps figures included, submitted to Phys. Lett. B
arxiv created 1997/08/16 · openalex publication_date 1997/10/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/04
Helicity density matrix elements for inclusive K∗(892)0 mesons from hadronic Z0 decays have been measured over the full range of K∗ 0 momentum using data taken with the OPAL experiment at LEP. A preference for occupation of the helicity zero state is observed at all scaled momentum xp values above 0.3, with the matrix element ϱ00 rising to 0.66 ± 0.11 for xp > 0.7. The values of the real part of the off-diagonal element ϱ1 - 1 are negative at large xp, with a weighted average value of −0.09 ± 0.03 for xp > 0.3, in agreement with new theoretical predictions based on Standard Model parameters and coherent fragmentation of the qq system from the Z0 decay. All other helicity density matrix elements measured are consistent with zero over the entire xp range. The K∗ 0 fragmentation function has also been measured and the total rate determined to be 0.74 ± 0.02 ± 0.02 K∗(892)0 mesons per hadronic Z0 decay.