V. Riquer

Diquark-Antidiquarks with Hidden or Open Charm and the Nature of X(3872)

Heavy-light diquarks can be the building blocks of a rich spectrum of states which can accommodate some of the newly observed charmoniumlike resonances not fitting a pure

New Look at Scalar Mesons

c\overline{c}

Four quark interpretation of Y ( 4260 )

assignment. We examine this possibility for hidden and open charm diquark-antidiquark states deducing spectra from constituent quark masses and spin-spin interactions. Taking the

The new pentaquarks in the diquark model

X(3872)

Indications of a four-quark structure for the X(3872) and X(3876) particles from recent Belle and BABAR data.

as input we predict the existence of a

A

{2}^{++}

J^{PG}=1^{++}

state that can be associated to the

Charged Resonance in the

X(3940)

Y(4260) \to \pi^+ \pi^- J/\psi

observed by Belle and reexamine the state claimed by SELEX,

Decay?

X(2632)