The production of J = 1++, 0−+ and 2−+ mesons in double tagged e+e− → e+e−R is calculated and found to have the same polarisation and dynamical characteristics as observed in pp → ppR. Implications for the spin structure of the Pomeron are considered. Production of 0++, 2++ mesons in these two processes may enable the dynamical nature of these mesons to be determined. 1 e-mail: [email protected]

We use lattice methods to evaluate from first principles the spectrum of hybrid mesons produced by gluonic excitations in quenched QCD with quark masses near the strange quark mass. For the spin-exotic mesons with J P C = 1 −+ , 0 +− , and 2 +− which are not present in the quark model, we determine the lightest state to be 1 −+ with mass of 2.0(2) GeV. Results obtained for orbitally excited mes...

The properties of vector mesons in nuclear matter are discussed. Results for the momentum dependence of the ρ-meson self energy in matter due to ρN interactions are presented, and consequences for the production rate of e+e− pairs in hot and dense matter are discussed. I also examine the constraints imposed by elementary processes on the widths of ρ and ω mesons in nuclear matter, and conclude ...

Despite the apparent simplicity of meson spectroscopy, light scalar mesons cannot be accommodated in the usual q ¯ q structure. We study the description of the scalar mesons below 2 GeV in terms of the mixing of a chiral nonet of tetraquarks with conventional q ¯ q states. A strong diquark-antidiquark component is found for several states. The consideration of a glueball as dictated by quenched...

We discuss the phenomenology of scalar and pseudoscalar mesons, emphasizing those which do not carry manifest flavor quantum numbers. Many of the properties of these mesons are still not fully understood. Some of them probably do not have the usual two-quark (quark-antiquark) structure, but may be mixed with glueball states or other exotics. We construct or discuss simple models for these meson...

Lattice QCD can give direct information on OZI-violating contributions to mesons. Here we explore the contributions that split flavour singlet and non-singlet meson masses. I discuss in detail the spectrum and decays for scalar mesons (ie including glueball effects). I also review the status of hybrid mesons and their decays. PACS. 12.38.Gc Lattice QCD calculations – 12.39.Mk Glueball and non-s...

We analyze three-body decays of and . Under the factorization approach, there are tree level diagrams for these decay modes and the transition matrix element of decay is factorized into a form factor multiplied by decay constant and form factor multiplied into weak vertices form factor. The transition matrix element of decay is also factorized into a form factor multiplied into weak vertic...

Recent results involving hadronic decays of charmed mesons and baryons are reviewed. Information relevant to decay mechanisms and to light quark scalar mesons is discussed.