The Pion Cloud of the Nucleon: Facts and popular Fantasies

I discuss the concept of the pion cloud surrounding the nucleon and other hadrons - and its limitations.Comment: 9 pp, 3 figs, invited talk, to appear in the proceedings of the workshop ``Shape of Hadrons'' (Athens, Greece, 2006

Some recent developments in chiral perturbation theory

In this talk, I address some recent developments in chiral perturbation theory at unphysical and physical quark masses.Comment: Plenary talk delivered at the 5th International Workshop on Chiral Dynamics, Theory and Experiment (CD 2006), September 18 - 22, 2006, Durham/Chapel Hill, NC, US

Chiral dynamics with strange quarks

In the first part of the talk, I review what we know (or rather do not know) about the structure of the QCD vacuum in the presence of strange quarks. Chiral perturbation theory allows to study reactions of pions and kaons and to further sharpen our understanding of symmetry violation in QCD. I review recent progress on the description of pion-kaon scattering, in particular concerning isospin violation and the extraction of threshold and resonance parameters from Roy-Steiner equations. In the third part, it is shown how a unitary extension of chiral perturbation theory leads to novel insight into the structure of the Lambda(1405).Comment: 10 pp, 3 figs, plenary talk, X. International Conference on Hadron Spectroscopy (HADRON '03), August 31 - September 6, 2003, Aschaffenburg, German

Nuclear lattice simulations: Status and perspectives

I review the present status of nuclear lattice simulations. This talk is dedicated to the memory of Gerald E. Brown.Comment: Plenary talk sponsored by The European Physical Journal A -- Hadrons and Nuclei, INPC 2013, Florence, Italy, 8 pages, 3 figures, uses webofc.cl

Quark mass dependence of baryon properties

I discuss the quark mass dependence of various baryon properties derived from chiral perturbation theory. Such representations can eventually be used as chiral extrapolation functions when lattice data at sufficiently small quark masses become available. The quark mass dependence is encoded in loop and contact term contributions, the latter given in terms of low-energy constants. I stress the importance of utilizing phenomenological input to constrain a certain class of low-energy constants and discuss the ensuing theoretical uncertainty for various baryon observables, like the nucleon and the baryon octet masses, the nucleon isovector anomalous magnetic moment and the axial-vector coupling of the nucleon. I stress the role of resonance decoupling and present first results for the delta mass based on an effective field theory in which the nucleon-delta mass splitting is counted as a small parameter. I also discuss briefly the pion mass dependence of the nuclear force as derived from chiral nuclear effective field theory.Comment: 21 pp, PoS style, plenary talk at Lattice 2005, Trinity College, Dublin, Irland, 25th-30th July 200