A brief introduction to chiral perturbation theory, the effective field theory of quantum chromodynamics at low energies, is given.

We investigate the phase structure of lattice QCD for general number of flavors NF . Based on numerical data combined with the results of the perturbation theory we propose the following picture: When NF ≥ 17, there is only one IR fixed point at vanishing gauge coupling, i.e., the theory in the continuum limit is trivial. On the other hand, when 16 ≥ NF ≥ 7, there is a non-trivial fixed point. ...

The antiproton storage ring HESR to be constructed at GSI will open up a new range of perturbative and nonperturbative tests of QCD in exclusive and inclusive reactions. I discuss 21 tests of QCD using antiproton beams which can illuminate novel features of QCD. The proposed experiments include the formation of exotic hadrons, measurements of timelike generalized parton distributions, the produ...

In these lectures I will discuss three central topics in quantum chromodynamics: (1) the use of light cone quantization and Fock space methods to determ ine the long and -short-distance structure of quark and gluon distributions within hadrons; (2) th e role of spin, heavy quarks, and nuclei in unraveling fundamental phenomenological features of QCD; and (3) a new approach to understanding the ...

We present a heuristic argument in support of the assertion that QCD will exhibit a mass gap, if the Callan-Symanzik function β(g) obeys the inequality β(g) < 0, for all g > 0. We begin by summarizing the standard lore attributed to QCD: (A) QCD must have a mass gap, i.e., every excitation above the vacuum state must have energy > △, where △ is a positive constant. The key idea that infrared sl...

I review some topics in lattice quantum chromodynamics, focusing more on the recent results. These include: (i) the QCD phase diagram in the μ–T plane, (ii) the quark number susceptibilities, and (iii) the screening lengths.

A generalized formalism of QCD multipole expansion including constituent quark field quantization is proposed. It can be applied to study soft-gluon emission processes of heavy quark-antiquark systems with quark flavor changing or quark pair annihilation. As an application, the radiative decays J/t+h + 7 + 77 and J/t) --t 7+7r” are studied in this framework. It is shown that J/$ + 7+~ is domina...

1 Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005, India 2 Centre for Theoretical Studies, Indian Institute of Science, Bangalore 560 012, India 3 Mehta Research Institute, Chhatnag Road, Jhusi, Allahabad 221 506, India 4 Rutherford Appleton Lab., Chilton, Didcot, Oxfordshire, OXl 1 0QX, England 5 The Institute of Mathematical Sciences, C.I.T. Campus, Taramani, Chennai ...