arXiv subjects

M. Genovese

Publications and source records attributed to M. Genovese.

131 records · Page 8Linked to original sources

arXiv1993

Perturbative QCD Forbidden Charmonium Decays and Gluonia

We address the problem of observed charmonium decays which should be forbidden in perturbative QCD. We examine the model in which these decays proceed through a gluonic component of the $J/Ψ$ and the $η_c$, arising from a mixing of $(c\bar c)$ and glueball states. We give some bounds on the values of the mixing angles and propose the study of the $p \bar{p} \to ϕϕ$ reaction, at $\sqrt{s} \simeq 3$ GeV, as an independent test of the model.

hep-ph↗

arXiv1993

Shadowing in deuterium and the small--$x$ limit of $F_2^n/F_2^p$ and $F_2^p - F_2^n$

We discuss the updated NMC determination of $F_2^n/F_2^p$ and $F_2^p - F_2^n$. Shadowing effects in deuterium make the structure functions determined by the NMC sensibly different from the true ones in the low--$x$ region. We show that the departure of $F_2^n/F_2^p$ and $F_2^p-F_2^n$ from the Regge expectations at small $x$ observed by the NMC likely disappears if one takes into account the shadowing corrections.

hep-ph↗

arXiv1993

Non universality of structure functions and measurement of the strange sea density

We show that there is no real conflict between the two determinations of the strange sea density from the opposite--sign dimuon production and from the difference of the $F_2$ structure functions measured in neutrino and muon deep inelastic scattering. Once non universal sea parton densities are introduced, which take into account the effects of different mass thresholds and different longitudinal contributions, the discrepancy is shown to disappear and both sets of data are simultaneously well reproduced. No need for a large strange sea content of the nucleon emerges.

hep-ph↗

arXiv1993

Unitarization of Structure Functions at Large ${\bf 1/x}$

We discuss the effects of the $s$-channel unitarization on the $x$ and $Q^{2}$ dependence of structure functions. The unitarization is implemented at the level of photoabsorption cross sections by resorting to the light--cone wave functions of virtual photons and to the diagonalization property of the scattering matrix in a basis of Fock states of the photon with fixed transverse size. Triple pomeron effects are also explicitly taken into account. We find large unitarity corrections to the structure functions at $x < 10^{-2}$. The results are in very good agreement with the existing NMC and the preliminary HERA data.

hep-ph↗

arXiv1993

Phenomenology of Spin Zero Mesons and Glueballs

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. %, hybrids, or four-quark states. We construct or discuss simple models for these mesons and point out which measurements can shed light on their composition.

hep-ph↗