123512923
Sequential fragmentation and rate oscillations in exclusive decays
Abstract We consider the decay of heavy quarkonia into two light mesons, and assume that quark-antiquark pairs are created sequentially when the final state is formed. We find quantum oscillations in the decay rate as a function of total energy. These oscillations can explain the energy dependence observed in the πϱ and K ∗ K channels at the J ψ and ψ ′ and predict the behaviour at the heavier Ψ family. In the mechanism we discuss, a given final state is produced only in a narrow range of the possible distances between the initial light quark and light antiquark.
118531983
Strong decays of heavy hadrons In HQET
The authors discuss the application of the tensor formalism of HQET to the strong decays of heavy hadrons. They treat both meson and baryon decays, and note that all of their results are in agreement with the `spin-counting' arguments of Isgur and Wise. They briefly discuss the possible extension of the formalism to include 1/m corrections.
119514278
Radiative transitions in heavy mesons in a relativistic quark model
The radiative decays of D*, B*, and other excited heavy mesons are analyzed in a relativistic quark model for the light degrees of freedom and in the limit of heavy quark spin-flavor symmetry. The analysis of strong decays carried out in the corresponding chiral quark model is used to calculate the strong decays and determine the branching ratios of the radiative D* decays. Consistency with the observed branching ratios requires the inclusion of the heavy quark component of the electromagnetic current and the introduction of an anomalous magnetic moment for the light quark. It is observed that not only D, but also B meson transitions within a heavy quark spin multiplet are affected by the presence of the heavy quark current.
56316663
Baryons in the heavy quark effective theory
We show how to incorporate baryons in the heavy quark effective theory. A convenient formalism is exhibited and applied to semileptonic weak decays of heavy baryons. In general, the heavy quark effective theory reduces the number of form factors necessary to describe the matrix elements for transitions among heavy baryons. We also note that in semileptonic weak decays of Δc one arrives at an important and experimentally testable prediction that two form factors suffice to describe this process. As a further application of the formalism we discuss exclusive production of heavy baryons in e+e− annihilation.
41501121
Can four-quark states be easily detected in baryon-antibaryon scattering?
We attempt to explain the experimental sparsity of diquonia candidates given the theoretical abundance of such states. We do this by investigating the lowest-order contributions of such states as intermediates in {ital p{bar p}} scattering into exclusive baryon-antibaryon final states. We find that the contributions depend on the partial widths for the meson-meson decays of the diquonia, and that resonant effects can be easily made to disappear. We conclude that if the meson-meson widths of diquonia are larger than about 50 MeV, most of these states will be extremely difficult to observe in {ital p{bar p}} scattering, for instance. We note that diquonia may offer a convenient means of describing some aspects of the dynamics of baryon-antibaryon scattering.
8325726
Phenomenological Lagrangian approach to two kaon photoproduction and pentaquark searches
We examine cross sections for the processes {gamma} N {yields} NK{bar K} in the framework of a phenomenological Lagrangian. We include contributions from {Lambda} and {Sigma} resonances up to spin 3/2, as well as those from an exotic {Theta}{sup +}. We allow the {Theta}{sup +} to have spin 1/2 or 3/2, with either positive or negative parity in each case. We also allow the state to be either isovector or isoscalar. We find that the scenario that most closely matches observations at Jefferson Laboratory requires a very large coupling of the {Theta}{sup +} to NK*.
120709149
Elastic scattering of 600-MeV protons from H, D, He-3, and He-4.
120869047
Elastic Scattering of 580-MeV Protons from He 3
The elastic differential cross section for $p$-$^{3}\mathrm{He}$ scattering has been measured at 580 MeV. The data are compared with a Glauber model calculation.