Antonio Morelos Pineda

Potential NRQCD: an effective theory for heavy quarkonium

Abstract Within an effective field theory framework we study heavy-quark–antiquark systems with a typical distance between the heavy quark and the antiquark smaller than 1/ Λ QCD . A suitable definition of the potential is given within this framework, while non-potential (retardation) effects are taken into account in a systematic way. We explore different physical systems. Model-independent results on the short distance behaviour of the energies of the gluonic excitations between static quarks are obtained. Finally, we show how infrared renormalons affecting the static potential get cancelled in the effective theory.

Heavy quarkonium physics

This report is the result of the collaboration and research effort of the Quarkonium Working Group over the last three years. It provides a comprehensive overview of the state of the art in heavy-quarkonium theory and experiment, covering quarkonium spectroscopy, decay, and production, the determination of QCD parameters from quarkonium observables, quarkonia in media, and the effects on quarkonia of physics beyond the Standard Model. An introduction to common theoretical and experimental tools is included. Future opportunities for research in quarkonium physics are also discussed.

Physics at BES-III

We give a detailed review of the construction of gauge invariant Lagrangians for free and interacting higher spin fields using the BRST approach developed over the past few years.This physics book provides detailed discussions on important topics in

Effective field theory for ultrasoft momenta in NRQCD and NRQED

\tau

Infrared behavior of the static potential in perturbative QCD

-charm physics that will be explored during the next few years at \bes3 . Both theoretical and experimental issues are covered, including extensive reviews of recent theoretical developments and experimental techniques. Among the subjects covered are: innovations in Partial Wave Analysis (PWA), theoretical and experimental techniques for Dalitz-plot analyses, analysis tools to extract absolute branching fractions and measurements of decay constants, form factors, and CP-violation and \DzDzb-oscillation parameters. Programs of QCD studies and near-threshold tau-lepton physics measurements are also discussed.

The heavy quarkonium spectrum at order mαs5lnαs

Abstract We propose an effective field theory for heavy quark-antiquark bound states once the soft gluons have been integrated out. We also new results for the matching between QCD (QED) and NRQCD (NRQED).

Heavy quark pair production near threshold with potential non-relativistic QCD

The definition of the quark-antiquark static potential is given within an effective field theory framework. The leading infrared divergences of the static singlet potential in perturbation theory are explicitly calculated.

Potential NRQED: The positronium case

Abstract We compute the complete leading-log terms of the next-to-next-to-next-to-leading-order corrections to potential NRQCD. As a by-product we obtain the leading logs at O ( mα s 5 ) in the heavy quarkonium spectrum. These leading logs, when Λ QCD ≪ mα s 2 , give the complete O ( mα s 5 ln α s ) corrections to the heavy quarkonium spectrum.

The static potential: lattice versus perturbation theory in a renormalon-based approach

Abstract We study the effect of the resummation of logarithms for t t ¯ production near threshold and inclusive electromagnetic decays of heavy quarkonium. This analysis is complete at next-to-next-to-leading order and includes the full resummation of logarithms at next-to-leading-logarithmic accuracy and some partial contributions at next-to-next-to-leading logarithmic accuracy. Compared with fixed-order computations at next-to-next-to-leading order the scale dependence and convergence of the perturbative series is greatly improved for both the position of the peak and the normalization of the total cross section. Nevertheless, we identify a possible source of large scale dependence in the result. At present we estimate the remaining theoretical uncertainty of the normalization of the total cross section to be of the order of 10% and for the position of the peak of the order of 100 MeV.

The Lamb Shift in Dimensional Regularisation

We discuss in detail potential NRQED (pNRQED), a previously proposed effective field theory for ultrasoft photons. The pNRQED lagrangian for the equal mass case is presented and it is shown that it correctly reproduces the positronium spectrum at order