Measurement of the spin density matrix for the rho0, K*(892)0 and Phi produced in Z0 decays.

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Phys.Lett.B 406 (1997) 271-286, 1997.
Inspire Record 444150 DOI 10.17182/hepdata.47452

The spin density matrix elements for the ϱ 0 , K ∗0 (892) and F produced in hadronic Z 0 decays are measured in the DELPHI detector. There is no evidence for spin alignment of the K ∗0 (892) and F in the region x p ≤ 0.3 ( x p = p p beam ), where ϱ 00 = 0.33 ± 0.05 and ϱ 00 = 0.30 ± 0.04, respectively. In the fragmentation region, x p ≥ 0.4, there is some indication for spin alignment of the ϱ 0 and K ∗0 (892), since ϱ 00 = 0.43 ± 0.05 and ϱ 00 = 0.46 ± 0.08, respectively. These values are compared with those found in meson-induced hadronic reactions. For the F, ϱ 00 = 0.30 ± 0.04 for x p ≥ 0.4 and 0.55 ± 0.10 for x p ≥ 0.7. The off-diagonal spin density matrix element ϱ 1-1 is consistent with zero in all cases.

3 data tables match query

Helicity density matrices elements. The statistical and systematic errors are combined quadratically.

Helicity density matrices elements. The statistical and systematic errors are combined quadratically.

Helicity density matrices elements. The statistical and systematic errors are combined quadratically.


Continuum charged D* spin alignment at s**(1/2) = 10.5-GeV.

The CLEO collaboration Brandenburg, G. ; Briere, Roy A. ; Ershov, A. ; et al.
Phys.Rev.D 58 (1998) 052003, 1998.
Inspire Record 467595 DOI 10.17182/hepdata.47207

A measurement of the spin alignment of charged D^* mesons produced in continuum e^+ e^- \to c \bar{c} events at \sqrt{s}=10.5 GeV is presented. This study using 4.72 fb^{-1} of CLEO II data shows that there is little evidence of any D^* spin alignment.

4 data tables match query

Systematic errors are not given.

Systematic errors are not given.

Two decay modes of D0 --> K- PI+ and D0 --> K- PI+ PI0 are combined.

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