Strong decays of radially excited vector mesons

Motivated by the recent discovery at Orsay of ?′ (1680), we study the strong interaction decays of radially excited vector mesons within the framework of the³ P ₀ quark pair creation model. We stress the relative importance of phase space, algebraic spinflavor couplings, and spatial overlaps. Quite a few features of the data can be will understood by the presence of a node in the spatial wave function, but the detailed structure of the modes ρ′→4π remains a serious challenge.     

Electromagnetic decays of light mesons

The new data on the electromagnetic decays of “light” mesons are analyzed. Special attention is paid to rare electromagnetic leptonic decays of the type $\text{A}\text{→}\text{B}\text{l}{}^{\mathrm{+}}\text{l}{}^{\mathrm{?}}$ and to ways of using these processes for extracting information on the transition form factors of neutral mesons. Data on electromagnetic lepton processes of higher order, such as $\text{P}\text{→}\text{l}{}^{\mathrm{+}}\text{l}{}^{\mathrm{?}}$ and $\text{P}\text{′ →}\text{P}\text{l}{}^{\mathrm{+}}\text{l}{}^{\mathrm{?}}$, are also analyzed and we discuss present prospects for such investigations.     

Two-body nonleptonic decays ofD mesons

The amplitudes for two-body Cabibbo allowed nonleptonic decays ofD mesons are evaluated within the factorization approximation from the effective Hamiltonian including short distance QCD corrections to next-to-leading order. Annihilation andW-exchange contributions as well as final state interaction effects have been included and are in fact crucial to obtain agreement with the experimental data.     

Inclusive semileptonic decays of B mesons

The probability of inclusive semileptonic decay of B mesons is calculated in the constituent-quark model. A compact formula is obtained for the differential decay width of a B meson in terms of the corresponding decay width of a free b quark and the wave function of the internal motion of the quarks in the B meson. Numerical values of semileptonic-decay widths are obtained for a series of models of the wave function. Pis’ma Zh. éksp. Teor. Fiz. 65, No. 10, 734–737 (25 May 1997)     

Nonleptonic weak decays of bottom mesons

Based on the Kobayashi-Maskawa weak current model we investigate the properties of weak hadronic decays of the anticipated bottom mesons. Our main results concern twobody and quasitwobody decays of bottom mesons into pseudoscalar and vector mesons.     

Lepton-number violating decays of heavy mesons

The experimental observation of lepton-number violating processes would unambiguously indicate the Majorana nature of neutrinos. Various ΔL=2 processes for pseudoscalar meson M ₁ decays to another pseudoscalar meson M ₂ and two charged leptons ? ₁, ? ₂ (\(M_{1}^{+}\rightarrow \ell_{1}^{+}\ell_{2}^{+}M_{2}^{-}\)) have been studied extensively. Extending the existing literature on the studies of these kinds of process, we consider the rare decays of heavy mesons to a vector meson or a pseudoscalar meson. These processes have not been searched for experimentally, while they may have sizable decay rates. We calculate their branching fractions and propose to search for these decay modes in the current and forthcoming experiments, in particular at the LHCb.     

Exclusive semileptonic decays of heavy mesons

Exclusive semileptonic decays of heavy mesons provide interesting information on systems consisting of quarks of unequal mass. We express the formfactors of the hadronic current in terms of relativistic bound state wave functions for which we take the solutions of a relativistic harmonic oscillator potential. The wave function overlap is determined by the quark mass dependent longitudinal momentum distribution and differs from results based on non relativistic wave functions. The semileptonic widths and lepton spectra are calculated using in addition nearest pole dominance for the momentum transfer dependence of the formfactors. We compare our results with recent experimental data. The formfactor calculation also allows an estimate of special nonleptonic transitions. From the CLEO results on \(\bar B^0 \to \pi ^ + \pi ^ -\) and \(\bar B^0 \to D^{* + } + \pi ^ -\) we find for the corresponding Kobayashi-Maskawa matrix element ratio the limit |V _ub /V _cb |?0.3.