Exclusive double quarkonium production and generalized TMDs of gluons

Quarks vs. Gluons in Exclusive Ρ Electroproduction

We compare the contributions from quark and from gluon exchange to the exclusive process γ * p → ρ 0 p. We present evidence that the gluon contribution is substantial for values of the Bjorken variable x B around 0.1. 1. There is an ongoing experimental and theoretical effort to determine generalized parton distributions [1, 2] from hard exclusive processes like deeply virtual Compton scatterin...

Power counting in exclusive quarkonium decays

Recent progress in the factorization of exclusive decays of heavy quarkonia into long-distance and short-distance contributions is presented. The role of higher Fock states and colour-octet contributions is outlined. To appear in the Proceedings of the High-Energy Physics Euroconference on Quantum Chromodynamics Montpellier, France, 3–9 July 1997 a Heisenberg Fellow. CERN–TH/97–253 September 1997

Quarkonium Production

Production & Decay of Quarkonium

In this talk I review NRQCD predictions for the production of charmonium at the Tevatron. After a quick presentation of the NRQCD factorization formalism for production and decay I review some old results and discuss how they compare to recent data. Following this I discuss some recent work done with Adam Leibovich and Ira Rothstein.

Quarkonium Production and Decay

With new data sets, recently completed analyses and renewed interest, there has been significant progress in addressing existing questions about quarkonia production and decay ... but also new questions and new confrontation with theory. Some highlights include the firm establishment of the η c and of the “missing” ψ ′ decays to 01 final states, improved information on the nature of the ψ(3770)...