相关论文: The Pion Cloud: Insights into Hadron Structure
We extend the QCD Parton Model analysis by employing a factorized nuclear structure model that explicitly accounts for both individual nucleons and correlated nucleon pairs. This novel framework establishes a paradigm that directly links…
We study how the electromagnetic structure of the nucleon is influenced by a pion cloud. To this aim we make use of a constituent-quark model with instantaneous confinement and a pion that couples directly to the quarks. To derive the…
This colloquium addresses the issue of the shape of hadrons and in particular that of the proton. The concept of shape in the microcosm is critically examined. Special attention is devoted to properly define the meaning of shape for…
After sketching some historical events related to Yukawa and Tomonaga concerning the birth of mesons, the author describes recent developments in the spectroscopy of pion-nucleus bound states via "pion-transfer" reactions. The role of pions…
This presentation reviews recent developments in the understanding of low-energy pion- and kaon-nucleon interactions as they relate to deeply bound pionic atoms and possible antikaon-nuclear bound states. A brief update is given on 1s…
This article reviews our present understanding of QCD spin physics: the proton spin puzzle and new developments aimed at understanding the transverse structure of the nucleon. We discuss present experimental investigations of the nucleon's…
The evolution of nuclear shell structure is investigated for the first time within density-dependent relativistic Hartree-Fock theory and the role of $\pi$-exchange potential is studied in detail. The energy differences between the neutron…
The description of the internal structure of hadrons is one of the main goal of QCD. At moderate energy scales, the hadronic representation succeeds to the partonic description, rendering challenging the description of the dynamics of…
The application of the chiral effective theory to processes with two or more nucleons is discussed. We gain a qualitative understanding of the gross features of nuclear physics and quantitative, testable postdictions and predictions…
The pseudoscalar particles pions, kaons and the $\eta$-particle are considerably lighter than the other hadrons such as protons or neutrons. Their lightness was understood as a consequence of approximate chiral symmetry breaking. This led…
It is a consequence of QCD's spontaneously broken chiral symmetry that the response of the neutron to long wavelength probes will be driven by excitation of its pion cloud. In this article I discuss manifestations of this in electromagnetic…
It is theoretically and experimentally argued that there may exist bubble or toroid-shaped configurations in some nucleus systems. Based on the nuclear transport model, it is shown that compared with the collision of normal nuclei, there is…
The state of the art in the study of pionic, kaonic and Sigmionic atoms, along with the in-medium nuclear interactions deduced for these hadrons, is reviewed. A special emphasis is placed on recent developments in antikaon-nuclear physics,…
Experimental data on electromagnetic and weak form factors of the nucleon are analyzed in a two-component model with a quark-like intrinsic structure surrounded by a meson cloud. The contribution from strange quarks is discussed and…
In this talk we review recent progress on the systematic evaluation of the kaon and antikaon spectral functions in dense nuclear matter based on a chiral SU(3) description of the low-energy pion-, kaon- and antikaon-nucleon scattering data.
Using the light-front pion wave function based on a Bethe-Salpeter amplitude model, we study the properties of the pion in symmetric nuclear matter. The pion model we adopt is well constrained by previous studies to explain the pion…
The current status of global QCD analysis of parton distribution functions of the nucleon is reviewed. Recent progress made in determining various features of the parton structure of the nucleon, as well as outstanding open questions are…
High-energy hadronic reactions with proton-to-neutron transitions (and vice versa) with small momentum transfer allow to study the properties of nearly on-shell pions, which cannot be accessed otherwise. We overview the recent results for…
In recent years the investigation of hadron structure using lattice techniques has attracted growing attention. In this talk we give an overview on recent work with a focus on results for nucleon spectrum and structure from the QCDSF…
In the quest to understand QCD there are a number of outstanding challenges. Here we focus on one of these, namely what one expects to happen to the structure of a hadron when it is immersed in a nuclear medium. We argue that the necessary…