B 0 s → D − s and B 0 s → D * − s weak transition form factors are estimated for the whole physical region with a method based on an instantaneous approximated Mandelstam formulation of transition matrix elements and the instantaneous Bethe-Salpeter equation. We apply the estimated form factors to branching ratios, CP asymmetries and polarization fractions of nonleptonic decays within the factorization approximation. And we study the non-factorizable effects and annihilation contributions with the perturbative QCD approach. The branching ratios of semi-leptonic B 0 s → D ( * )− s l + ν l decays are also evaluated. We show that the calculated decay rates agree well with the available experimental data. The longitudinal polarization fraction of B s → D * s V (A) decays are ∼ 0.8 when V (A) denotes a light meson, and are ∼ 0.5 when V (A) denotes a D q (q = d, s) 1 adopted QCDSR for the calculation. In [14], the form factors are estimated within the covariant light-front quark model (CLFQM). Authors of [15] used the so called light cone sum rules (LCSR) to investigate form factors at large recoil, and heavy quark effective theory (HQET) to describe them at small recoil region. Each of these methods sketches one or another profile of non-perturbative QCD, and each has advantages as well as shortcomings. So it is worthy to estimate the B s → D ( * ) s form factors in another method which is based on the B-S equation [16] and the Mandelstam formulation [17] of the transition matrix element. To make predictions on non-leptonic decays, there is another task, that is how to evaluate the decay amplitudes with form factors available. It is well known that factorization approximation (FA) [11] has been extensively applied in non-leptonic weak decays and has been justified to success in explaining the branching ratios of several color-allowed B q decays [18]. The works mentioned before all adopted the FA to evaluate non-leptonic decay amplitudes. However, estimations based on the FA still suffer uncertainties from the non-factorizable effects and annihilation diagrams contributions, especially for the CP asymmetries (CPAs). Thus approaches beyond the FA are in need. Till now several approaches which can cover the non-factorizable effects have been developed, such as the perturbative QCD (pQCD) approach [19], the QCD improved factorization (QCDF) approach [20] and SCET approach [21]. Studies on B s decays into charmed particles with the perturbative QCD approach have been carried out in [22]. In this work, we evaluate non-leptonic decay amplitudes under FA, as well as estimate non-factorizable and annihilation contributions in the pQCD approach. Besides these direct calculation in the FA or pQCD, the authors in [23] used SU(3) F symmetry to estimate the widths of a class of two-body B s decays with the help of experimental data of corresponding B decays. There have been some studies on semi-leptonic B 0 s → D ( * )− s l + ν l decays with the approaches such as QCDSR [13], LCSR [15], CLFQM [14] and constituent quark meson mod...

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The multiparticle Bose-Einstein correlations for quark-gluon plasma ͑QGP͒ formation in high energy heavy ion collisions are analyzed. The average correlation intensities of multipions as a function of pion multiplicity are investigated. It is shown that the average correlation intensities of multipions have obvious enhancements in the high multiplicity region. This signature can be used to detect the existence of QGP in rare high pion multiplicity events in high energy heavy ion collisions. ͓S0556-2813͑98͒05509-5͔PACS number͑s͒: 25.75. Ϫq, 24.85.ϩp, 12.38.Mh