Aspects Of Charmonium Physics In Lattice Qcd

Charmonium states provide a relevant source of knowledge for determining fundamental parameters of the Standard Model. An important aspect of understanding Quantum ChromoDynamics (QCD) is to make precise predictions of the hadron spectrum and to test them against high-quality experimental data. Our theoretical framework is Lattice QCD, which is considered to be the only known way to treat the full QCD Lagrangian non perturbatively from first principles, in a manner well suited to numerical computation. By using the Wilson-Clover action with N_f = 2 dynamical flavors, we will study the two charmonium mesons eta_c and J/ psi. We will also investigate some properties of their first radial excitations eta_c(2S) and psi(2S).

Charmonium is an attractive system for the application of lattice QCD methods owing to the possibility of computing with the physical quark mass in a reasonable time. While the sub-threshold spectrum has been considered in some detail in previous works, it is only very recently that further properties such as radiative transitions and two-photon decays have come to be calculated; herein we discuss this recent progress.

Properties of excited mesons are studied using a lattice QCD simulation of a system comparable to charmonium. We extract a spectrum of states, including those with manifestly exotic quantum numbers. Radiative transition form-factors are also computed, in particular the transition from exotic ·c1 to J /È 3 which is found to be large on the usual scale of magnetic dipole transitions.

Particle and nuclear physicists frequently take results from Lattice QCD at their face value without probing into their reliability or sophistication. This attitude usually stems from a lack of knowledge of the field. The aim of the present volume is to rectify this by introducing in an elementary way several topics, which we believe are appropriate for, and of possible interest to, both particle and nuclear physicists who are non-experts in the field.

Lattice field theory is the most reliable tool for investigating non-perturbative phenomena in particle physics. It has also become a cross-discipline, overlapping with other physical sciences and computer science. This book covers new developments in the area of algorithms, statistical physics, parallel computers and quantum computation, as well as recent advances concerning the standard model and beyond, the QCD vacuum, the glueball, hadron and quark masses, finite temperature and density, chiral fermions, SUSY, and heavy quark effective theory.

The aim of this book is to offer to the next generation of young researchers a broad and largely self-contained introduction to the physics of heavy ion collisions and the quark-gluon plasma, providing material beyond that normally found in the available textbooks. For each of the main aspects - QCD thermodynamics and global features of the QGP, collision hydrodynamics, electromagnetic probes, jet and quarkonium production, color glass condensate, and the gravity connection - the present volume provides extensive and pedagogical lectures, surveying the present status of both theory and experiment. A particular feature of this volume is that all lectures have been written with the active assistance of selected students present at the course in order to ensure the adequate level and coverage for the intended readership.

This exhaustive survey is the result of a four year effort by many leading researchers in the field to produce both a readable introduction and a yardstick for the many upcoming experiments using heavy ion collisions to examine the properties of nuclear matter. The books falls naturally into five large parts, first examining the bulk properties of strongly interacting matter, including its equation of state and phase structure. Part II discusses elementary hadronic excitations of nuclear matter, Part III addresses the concepts and models regarding the space-time dynamics of nuclear collision experiments, Part IV collects the observables from past and current high-energy heavy-ion facilities in the context of the theoretical predictions specific to compressed baryonic matter. Part V finally gives a brief description of the experimental concepts. The book explicitly addresses everyone working or planning to enter the field of high-energy nuclear physics.