Hadronic Masses and Regge Trajectories

A comprehensive phenomenological analysis of experimental data and some theoretical models is presented here (for mesons) to critically discuss how Regge trajectory parameters depend on flavor. Through analytic continuation of physical trajectories (obtained from resonance data) into the space like region, we derive the suppression factor for heavy flavor production. The case of our D Regge exchange, both for D and $\Lambda_c$ production, is considered in some detail. Good agreement with data is reached confirming that indeed the slopes of heavier flavors decrease. This result suggests that the confinement potential has a substantial dependence on the quark masses. In a simple non-relativistic model, constrained to produce linear Regge trajectories, it is shown that a linear quark mass dependence is required (in the confinement part of the potential) in order for the slope to decrease in the appropriate way.Comment: 19 pages, 9 Figures, IV Table

On asymmetry in inclusive pion production

On the basis of the mechanism proposed for one-spin asymmetries in inclusive hadron production we specify an $x$--dependence of asymmetries in inclusive processes of pion production. The main role in generation of this asymmetry belongs to the orbital angular momentum ofquark-antiquark cloud in internal structure of constituent quarks. The $x$--dependence of asymmetries in the charged pion production at large $x$ reflects the corresponding dependence of constituent quark polarization in the polarized proton.Comment: LaTeX, 8 pages, 3 figures. One figure added, as it appears in Phys. Rev.

Measurement of the b hadron lifetime with the dipole method

A measurement of the average lifetime of b hadrons has been performed with the dipole method on a sample of 260000 hadronic Z decays recorded with the ALEPH detector during 1991. The dipole is the distance between the vertices built in the opposite hemispheres. The mean dipole is extracted from all the events without attempting b enrichment. Comparing the average of the data dipole distribution with a Monte Carlo calibration curve obtained with different b lifetimes, an average b hadron lifetime of 1.51 +/- 0.08 ps is extracted