[en] The study of lifetimes and semileptonic (SL) decays of charmed mesons and baryons is currently the goal of several experiments all around the world. This paper is focussed on giving an overview of current status and open questions, and on reviewing new results by E687 and CLEO presented as contributed papers at the 1995 international europhysics conference on high energy physics, held at Brussel (Belgium), July 27-August 2, 1995. A wealth of detailed reviews exists on both charm lifetime up-to-date, which the reader can refer to for details

[en] The paper reviews the latest progress on the observation of new heavy mesons and the non-rare decays of heavy mesons

[en] We discuss the calculation of open heavy flavor cross sections at RHIC and describe how the semileptonic decays of charm and bottom quarks can be separated.

[en] Recent measurements of inclusive and exclusive semi-leptonic b branching ratios are reviewed. Model-independent analyses from ARGUS and CLEO confirm the value BR(b → lνX) 0 10.4%, while new analyses from ALEPH obtain higher values above 11%. The difference is not consistent with measured values of b hadron lifetime. New measurements of BR(B → D^*lν) from CLEO and ALEPH are in good agreement. First measurements of B → D^*πlν branching ratios from OPAL, DELPHI, and ALEPH confirm indirect evidence for a large D^** component in semi-leptonic B decays

[en] We propose a new method for identifying and isolating Q(bar Q)+jet events through semileptonic decays of the Q(bar Q) pair. Employing these decay dileptons to tag the jet in a specific kinematic region provides a clean signature of jets associated with heavy quark production. The measurement, in both pp and heavy-ion collisions, is essential for addressing heavy quark fragmentation in the vacuum and in a dense medium. We present next-to-leading order calculations of Q(bar Q) production (leading order in Q(bar Q)+jet production) in √s = 14 TeV pp collisions at the LHC and discuss the feasibility of the measurement in heavy-ion collisions at √s_NN = 5.5 TeV

[en] Estimates of the branching ratios for B_d,s→Jψ η and B_d,s→η l+l- are obtained by SU(3) relation to B_d→Jψ K and B_d→K l+l-, respectively, as functions of the η mixing parameter, θ_P. Based on these estimates, a discussion of the prospects for HERA-B, CDF-II, and ATLAS on these processes is given. The CP violation in B_d,s→ Jψ η is analyzed in depth and a method to extract the angle gamma of the unitarity triangle is discussed. Finally, a possible method to constrain the Wilson coefficient C_10A from measurements on semileptonic B decays such as B_d→Jψ K and B_s→η l+l- is proposed along with a discussion of the prospects for future experiments and form factor calculations to reach the precision required for this method to be interesting. (author)

[en] The authors present a method for parameterizing heavy-meson semi-leptonic form factors using dispersion relations, and form it produce a two-parameter description of the B → B elastic form factor. The authors use heavy-quark symmetry to relate this function to B → D^*lν form factors, and extract V_cb = 0.0355_-0.0025⁺0.0029 from experimental data with a least-squares fit. This methods eliminates model-dependent uncertainties inherent in choosing a parametrization for the extrapolation of the differential decay rate to threshold

[en] In this talk we discuss finite-volume computations of two-body hadronic decays below the inelastic threshold (e.g. K → ππ decays). In particular we show how the relation between finite-volume matrix elements and physical amplitudes, recently derived by Lellouch and Luescher, can be extended to all elastic states under the inelastic threshold. We also provide a derivation of the Luescher quantization condition directly in quantum field theory

[en] It is shown that certain double ratios introduced for computing semileptonic form factors are accurate to order l/m²_Q, even when the action and current are accurate to order 1/^mQ

[en] We determine matrix elements for B → D semileptonic decay. The use of the constrained fitting method and multiple smearings for both two- and three-point correlators allows an improved calculation of the form factors