Pion structure functions from lattice QCD

We compute 〈x〉 and 〈x²〉 of the valence quarks in a pion, on the lattice using Wilson fermions in the quenced approximat We find 〈x〉 = 0.49±0.08 and 〈x²〉 = 0.02 at a scale μ ≅ 7 GeV, in a good agreement with experimental data.     

In-medium QCD and Cherenkov gluons

The equations of in-medium gluodynamics are proposed. Their classical lowest order solution is explicitly shown for a color charge moving with constant speed. For nuclear permittivity larger than 1 it describes emission of Cherenkov gluons resembling the results of classical electrodynamics. The choice of nuclear permittivity and Lorentz invariance of the problem are discussed. Effects induced by the transversely and longitudinally moving (relative to the collision axis) partons at LHC energies are described.     

Hadron wave functions in lattice QCD

Coulomb gauge quark-antiquark wave functions for the pion and the rho are calculated in the valence approximation on a lattice 8³ × 16. We use gauge group SU(2) at β of 2.431 corresponding to an inverse lattice spacing of 1100 ± 100 MeV. The wave functions fall off significantly over the size of the box, are rotationally invariant except at the box's boundary, and are nearly independent of the lagrangian quark mass.     

QCD thermodynamics from the lattice

We review the current methods and results of lattice simulations of quantum chromodynamics at nonzero temperatures and densities. The review is intended to introduce the subject to interested nonspecialists and beginners. It includes a brief overview of lattice gauge theory, a discussion of the determination of the crossover temperature, the QCD phase diagram at zero and nonzero densities, the equation of state, some in-medium properties of hadrons including charmonium, and some plasma transport coefficients.     

Parton distributions from lattice QCD

We extract the x dependence of the valence nonsinglet u - d distribution function in the nucleon from the lowest few moments calculated on the lattice, using an extrapolation formula which ensures the correct behavior in the chiral and heavy quark limits. We discuss the implications for the quark mass dependence of meson masses lying on the J^PC = 1^{– -} Regge trajectory.     

Baryon-Baryon interactions from lattice QCD

We report on new attempt to investigate baryon-baryon interactions in lattice QCD. From the Bethe-Salpeter (BS) wave function, we have successfully extracted the nucleon-nucleon (NN) potentials in quenched QCD simulations, which reproduce qualitative features of modern NN potentials. The method has been extended to obtain the tensor potential as well as the central potential and also applied to the hyperon-nucleon (YN) interactions, in both quenched and full QCD.     

Nuclear physics from lattice QCD

We review recent progress toward establishing lattice Quantum Chromodynamics as a predictive calculational framework for nuclear physics. A survey of the current techniques that are used to extract low-energy hadronic scattering amplitudes and interactions is followed by a review of recent two-body and few-body calculations by the NPLQCD collaboration and others. An outline of the nuclear physics that is expected to be accomplished with Lattice QCD in the next decade, along with estimates of the required computational resources, is presented.     

Baryon-Baryon interactions from lattice QCD

We report on new attempt to investigate baryon-baryon interactions in lattice QCD.From the Bethe-Salpeter （BS） wave function,we have successfully extracted the nucleon-nucleon （NN） potentials in quenched QCD simulations,which reproduce qualitative features of modern NN potentials.The method has been extended to obtain the tensor potential as well as the central potential and also applied to the hyperonnucleon （YN） interactions,in both quenched and full QCD.     

Nuclear force from lattice QCD

The nucleon-nucleon (NN) potential is studied by lattice QCD simulations in the quenched approximation, using the plaquette gauge action and the Wilson quark action on a 32(4) [approximately (4.4 fm)(4)] lattice. A NN potential V(NN)(r) is defined from the equal-time Bethe-Salpeter amplitude with a local interpolating operator for the nucleon. By studying the NN interaction in the (1)S(0) and (3)S(1) channels, we show that the central part of V(NN)(r) has a strong repulsive core of a few hundred MeV at short distances (r approximately < 0.5 fm) surrounded by an attractive well at medium and long distances. These features are consistent with the known phenomenological features of the nuclear force.     

Hadron spectroscopy from lattice QCD

I present recent developments in the lattice QCD calculations of the light hadron spectrum. Emphasis is placed on the failure of the quenched approximation in reproducing the observed spectrum and indications that the discrepancy is reduced by introducing two flavors of light dynamical quarks.     

Nucleon structure from lattice QCD

The aim of these lectures will be to provide an introductory overview of the concepts needed to compute hadronic matrix elements on the lattice from which moments of Generalised Parton Distributions (GPDs) are extracted and to highlight the contributions that current lattice calculations are making to this exciting field of research. Interesting related topics that will be covered include recent work on the nucleon electromagnetic form factors and moments of parton distribution functions, including the nucleon's axial coupling constant, g_A, and the average fraction of the nucleon's momentum carried by the quarks, 〈 x_q〉.     

Extracting glueball masses from lattice QCD

A general transfer matrix approach to extracting bound-state masses from lattice field theory is presented. Applications are made to SU(2) and SU(3) pure gauge theories. Employing a source of variable strength in the Monte Carlo simulation provides an efficient technique. The lowest mass glueball is found to have a mass of 1.0 ± 0.3 GeV, consistent with other evaluations.     

The hadron spectrum from lattice QCD

Determining the hadron spectrum and hadron properties beyond the ground states is a challenge in lattice QCD. Most of these results have been in the quenched approximation but now we are entering the dynamical era. I review some of the ideas and methods of the lattice approach, concentrating on a few examples and on results obtained for Chirally Improved (CI) fermions.     

Nucleon distribution amplitudes from lattice QCD

We calculate low moments of the leading-twist and next-to-leading-twist nucleon distribution amplitudes on the lattice using two flavors of clover fermions. The results are presented in the MS[over ] scheme at a scale of 2 GeV and can be immediately applied in phenomenological studies. We find that the deviation of the leading-twist nucleon distribution amplitude from its asymptotic form is less pronounced than sometimes claimed in the literature.