[en] The authors discuss the calculation of the width difference ΔΓ_B, between the B_s mass eigenstates to next-to-leading order in the heavy quark expansion. 1/m_b-corrections are estimated to reduce the leading order result by typically 30%. The error of the present estimate (ΔΓ/Γ)_Bs = 0.16_-0.09^+0.11 could be substantially improved by pinning down the value of < anti B_s|(anti b_is_i)_S-P(anti b_js_j)_S-P|B_s> and an accuracy of 10% in (ΔΓ/Γ)_Bs should eventually be reached. They briefly mention strategies to measure (ΔΓ/Γ)_Bs, and its implications for constraints on ΔM_Bs, CKM parameters and the observation of CP violation in untagged B_s samples

[en] We show that the bound-state approach to the strange dibaryons in the Skyrme model can be considerably simplified by omitting the Skyrme stabilizing term proportional to e^-2 and using the regularized version of the quantum stabilization proposed by Mignaco and Wulck. The strange dibaryons are obtained as systems consisting of bound antikaons in a (variational) axially symmetric SU(2)-skyrmion background field with baryon number B>1. (orig.)

[en] Experiment E760, at the FNAL anti p Accumulator, is dedicated to the study of charmonium formation in p anti p annihilation. New measurements of the total width and mass of narrow ( anti cc) states and of the partial width of the χ₂ state to γγ are presented. The first evidence for the h_c(¹P₁) singlet state is discussed in detail. (orig.)

[en] Using the recently proposed roughened string potential for heavy quarkonium, we calculate the spin splitting in the J/ψ and Υ systems. We show how the departure from linearity of this potential affects the hyperfine splitting in the P levels of these systems, in a way consistent with experimental data. This lends support to the recent observations that the confining part of the interquark potential is weaker than linear

[en] In this short note it is pointed out that the instanton model, which was theoretically fascinating, has recently found application in explaining the hyperfine splitting of mesons and baryons. In particular, the flavour independence of M_v²-M_P² (i.e. the squared mass difference of the vector and the pseudoscalar mesons), known to be constant for the strange and non-strange mesons in the u, d and the charm quark sectors, have recently been shown to be the same for the beauty sector through experiments. This flavour independence and the magnitude of the splitting agrees remarkably well with the instanton model. (author). 13 refs

[en] Several experiments plan to exploit the copious production of B-particles at the Tevatron. In this paper the prospects are discussed for the present and next generation of beauty experiments in both the fixed-target and collider programs at Fermilab. (orig.)

[en] The production of Φ-mesons on nuclear targets (carbon, aluminium and copper) by high-energy neutrons was analyzed. The dependence of the Φ-production cross section ratios on the nuclear mass number A was parametrized by the power law A^α with α=0.81±0.06. Within the sensitive kinematic range χ>0 and p_T<1 GeV/c no dependence was observed of exponent α on the longitudinal or transverse momentum. A possible interpretation of the measured dependence on A is discussed in the Appendix. (author) 3 tabs., 6 figs., 13 refs

[en] Results of the investigation of π⁰-meson photoproduction on ⁶Li, ¹²C, ²⁷Al, Cu, Cd (Cu and Cd being the natural isotope mixture) nuclei at small angles in the Δ₃₃-resonance region are presented. The differential cross sections in the γ-quanta energy range in the laboratory system ∼300-450 MeV and average emission angle in the c.m.s. ≅8.4 deg are given. The data for ⁶Li, ¹²C, ²⁷Al are compared to available calculations in the impulse approximation with both plane and distorted waves. The estimation of the resonance parameters of the Δ₃₃-isobar are made and A^α dependence of cross sections is investigated. The main characteristics of the experimental set-up are presented

[en] We discuss applications of QCD sum rules to mesons containing one heavy quark in the infinite mass limit, accounting for finite mass and low-loop corrections. We treat on the same footing both the pseudoscalar (B) and the vector (B^*) mesons, and derive values for their leptonic constants. We also show that, for suitable choices of parameters, it is possible in this framework to account for the B^*-B mass splitting. (orig.)

[en] From a sample of approximately 135 000 hadronic Z⁰ decays recorded with the OPAL detector, 1 536 events were selected with two lepton candidates, either electrons or muons. A signal for B⁰-anti B⁰ mixing was observed using the sign of the lepton charge to tag the charge of the b quark in decaying b-flavoured hadrons. A flavour discriminating variable was constructed from the lepton momentum and its component perpendicular to the jet axis. By fitting the fraction of events in which the two lepton charges are of the same sign, as a function of this variable, the average mixing parameter was measured to be χ=0.145(+0.041-0.035)±0.18, where the first error is statistical and the second is systematic. (orig.)