Final-state interaction and screening have a great influence on qq̄ production cross sections, which are important quantities in many problems in quark-gluon plasma physics. They lead to an enhancement of the cross section for a qq̄ color-singlet state and a suppression for a color-octet state. The effects are large near the production threshold. The presence of screening gives rise to resonances...

X iv :h ep -p h/ 97 06 44 5v 1 2 2 Ju n 19 97 Final-state Interaction Effects on Inclusive Two-particle Production in Electron-positron Annihilation∗ Jian-Jun Yang and Wei Lu 1. Department of Physics, Nanjing Normal University, Nanjing 210024, P.R. China 2. Institute of High Energy Physics, P.O. Box 918(4), Beijing 100039, P.R. China 3. Centre de Physique Théorique, Ecole Polytechnique, 91128 P...

We study phenomenologically the invariant mass spectra of scalar dipion states produced in cascade decays of excited Υ and ψ, and J/ψ decays into light vector mesons. The dipion production amplitude is given as a product in the Born term and an effective scalar form factor written in terms of a unitarized chiral theory. The model reproduces the experimental mass spectra very well. @ @ @ @ @ @@ @ @

We make an attempt to discuss in detail the effects originating from the final state interaction in the processes involving production of unstable elementary particles and their subsequent decay. Two complementary scenarios are considered: the single resonance production and the production of two resonances. We argue that part of the corrections due to the final state interaction can be connect...

The total photoabsorption cross sections of 6He and 6Li are calculated microscopically with full inclusion of the six-nucleon final state interaction using semirealistic nucleon-nucleon potentials. The Lorentz Integral Transform (LIT) method and the effective interaction approach for the hyperspherical formalism are employed. While 6Li has a single broad giant resonance peak, there are two well...

The polarization measurement in the inclusive B decay provides us with a simple test of how much the long-distance final-state interaction takes place as the energy of the observed meson varies in the final state. We give the expectation of perturbative QCD for the energy dependence of the helicity fractions in a semiquantitative form. Experiment will tell us for which decay processes the pertu...

It was shown that different mechanisms of perturbation of spontaneous decay constant: inelastic interaction of emitted particles with particle detector, decay onto an unstable level, Rabi transition from the final state of decay (electromagnetic field domination) and some others are really the special kinds of one general effect — perturbation of decay constant by dissipation of the final state...