On the Physical Relevance of the Study of gamma* gamma -> pi pi at small t and large Q2

We discuss the relevance of a dedicated measurement of exclusive production of a pair of neutral pions in a hard {gamma}*{gamma} scattering at small momentum transfer. In this case, the virtuality of one photon provides us with a hard scale in the process, enabling us to perform a QCD calculation of this reaction rate using the concept of Transition Distribution Amplitudes (TDA). Those are related by sum rules to the pion axial form factor F{sub A}{sup {pi}} and, as a direct consequence, a cross-section measurement of this process at intense beam electron-positron colliders such as CLEO, KEK-B and PEP-II, or Super-B would provide us with a unique measurement of the neutral pion axial form factor F{sub A}{sup {pi}0} at small scale. We believe that our models for the photon to meson transition distribution amplitudes are sufficiently constrained to give reasonable orders of magnitude for the estimated cross sections. Cross sections are large enough for quantitative studies to be performed at high luminosity e{sup +}e{sup -} colliders. After verifying the scaling and the {phi} independence of the cross section, one should be able to measure these new hadronic matrix elements, and thus open a new gate to the understanding of the hadronic structure. In particular, we argued here that the study of {gamma}*{gamma} {yields} {pi}{sup 0}{pi}{sup 0} in the TDA regime could provide with a unique experimental measurement of the {pi}{sup 0} axial form factor

Characteristics of charged multiplicity distributions in pi- d interactions at 200 GeV/c

Preliminary results on the charged particle multiplicity distribution will be presented and compared with results from {pi}{sup -}p interactions at 200 GeV/c. The data are derived from a 70,000 picture exposure of the Fermilab 30-inch deuterium filled bubble chamber to a beam of 200 GeV/c {pi}{sup -} particles

Neutral particle production in pi- d reactions at 200 GeV/c

Characteristics of {pi}{sup o} production and K{sup o}, {Lambda}, {bar {Lambda}}, production in {pi}{sup -}d interactions at 200 GeV are presented. The data are obtained from a 70,000 picture exposure of the FNAL 30-inch deuterium-filled bubble chamber. Comparison with pion proton data at similar energies and pion deuterium data at lower energies are made

A search for charmed particles in pi- d at 200 GeV/c

The authors have searched for evidence of charmed production in {pi}{sup -}d interactions by examining a sample of pictures from the FNAL 30-inch bubble chamber. A downstream muon detector was used to tag events in which a muon emerged. Results of the search is presented