Λb polarization in Z0 decays at LEP

Semi-inclusive decays Λb → Xc + (Ds, D ∗ s) at O(αs) including Λb and D ∗ s polarization effects

Semi-inclusive decays Λb → Xc + (Ds, D ∗ s) at O(αs) including Λb and D ∗ s polarization effects

Photon polarization from helicity suppression in radiative decays of polarized Λb to spin-3/2 baryons

We give a general parameterization of the Λb → Λ(1520)γ decay amplitude, applicable to any strange isosinglet spin-3/2 baryon, and calculate the branching fraction and helicity amplitudes. Large-energy form factor relations are worked out, and it is shown that the helicity-3/2 amplitudes vanish at lowest order in soft-collinear effective theory (SCET). The suppression can be tested experimental...

Color-octet heavy quarkonium productions in Z decays at LEP

We consider the energy and the polar angle distributions of J/ψ’s produced via the color-singlet and the color-octet (3S (8) 1 ) mechanisms in Z 0 → J/ψ+X at LEP. Since both distributions of the J/ψ produced via color-octet mechanism are significantly different from those via color-singlet mechanism, these observables can be used as tests of color-octet production mechanism for heavy quarkonia....

Axial Anomaly Effects in Pion and Z0 Radiative Decays

We discuss a connection between axial anomaly and polarized radiative processes. By comparison with the corresponding unpolarized cases, we consider some physical outputs for the π+ and Z0 polarized radiative decays. We analyse in detail the pattern of mass singularity cancellation. PACS 11.30.Rd, 13.20.Cz, 11.15.Bt