Effective lagrangians for bound state problems in QED, QCD, and other field theories
TL;DR: A renormalization group strategy for the study of bound states in field theory is developed in this paper, which is completely different from conventional analyses, based upon the Bethe-Salpeter equation, and it is far simpler
About: This article is published in Physics Letters B.The article was published on 1986-02-20. It has received 905 citations till now. The article focuses on the topics: Quantum chromodynamics & Ground state.
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Technische Universität München1, Novosibirsk State University2, Cornell University3, University of California, Davis4, Lawrence Livermore National Laboratory5, Argonne National Laboratory6, Fermilab7, Florida State University8, Indiana University9, Brookhaven National Laboratory10, Wayne State University11, University of Paris-Sud12, GSI Helmholtz Centre for Heavy Ion Research13, Ohio State University14, University of Regensburg15, University of Ferrara16, Polish Academy of Sciences17, University of Bari18, Max Planck Society19, Lancaster University20, Peking University21, Thomas Jefferson National Accelerator Facility22, University of Auvergne23, University of Cincinnati24, Stanford University25, University of Alberta26, Forschungszentrum Jülich27, University of Hawaii28, Illinois Institute of Technology29, Lawrence Berkeley National Laboratory30, École Polytechnique31, Budker Institute of Nuclear Physics32, CERN33, Université catholique de Louvain34, Pratt Institute35, University of São Paulo36, Seoul National University37, Tsinghua University38, Stony Brook University39, University of Valencia40, University of Milan41, Tohoku University42, University of Minnesota43
TL;DR: The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress as mentioned in this paper.
Abstract: A golden age for heavy-quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the B-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations at BESIII, the LHC, RHIC, FAIR, the Super Flavor and/or Tau-Charm factories, JLab, the ILC, and beyond. The list of newly found conventional states expanded to include h(c)(1P), chi(c2)(2P), B-c(+), and eta(b)(1S). In addition, the unexpected and still-fascinating X(3872) has been joined by more than a dozen other charmonium- and bottomonium-like "XYZ" states that appear to lie outside the quark model. Many of these still need experimental confirmation. The plethora of new states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of c (c) over bar, b (b) over bar, and b (c) over bar bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. Lattice QCD has grown from a tool with computational possibilities to an industrial-strength effort now dependent more on insight and innovation than pure computational power. New effective field theories for the description of quarkonium in different regimes have been developed and brought to a high degree of sophistication, thus enabling precise and solid theoretical predictions. Many expected decays and transitions have either been measured with precision or for the first time, but the confusing patterns of decays, both above and below open-flavor thresholds, endure and have deepened. The intriguing details of quarkonium suppression in heavy-ion collisions that have emerged from RHIC have elevated the importance of separating hot- and cold-nuclear-matter effects in quark-gluon plasma studies. This review systematically addresses all these matters and concludes by prioritizing directions for ongoing and future efforts.
1,354 citations
TL;DR: In this paper, the authors exploit these static quark symmetries to derive model-independent normalizations of some weak hadronic matrix elements involving heavy quarks, as well as many relationships between such matrix elements.
1,322 citations
Book•
31 Jul 1992TL;DR: In this paper, the S = 1 interaction was introduced and the Kaon mixing and CP violation was investigated in the context of the large N expansion of the standard QCD model.
Abstract: Preface Inputs to the standard model Interactions of the standard model Symmetries and anomalies Introduction to effective Lagrangians Leptons Very low energy QCD - Pions and photons Introducing kaons and etas Kaons and the S=1 interaction Kaon mixing and CP violation The large N expansion Phenomenological models Baryon properties Hadron spectroscopy Weak interactions of heavy quarks The Higgs boson The electroweak gauge bosons Appendices References Index.
1,058 citations
[...]
TL;DR: In this paper, the authors studied the performance of a SU (2 ) L fermion quintuplet with mass 4.4 TeV, accompanied by a charged partner 166 MeV heavier with life-time 1.8 cm, that manifests at colliders as charged tracks disappearing in π ± with 97.7% branching ratio.
988 citations
[...]
TL;DR: In this article, the authors review the current status of heavy-quark symmetry and its applications to weak decays of hadrons containing a single heavy quark, including a comprehensive treatment of symmetry breaking corrections.
978 citations
References
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01 Jan 1957
TL;DR: The theory of atoms with one or two electrons is the simplest and most completely treated field of application of quantum mechanics as mentioned in this paper, and it is one of the simplest fields of application for quantum mechanics.
Abstract: One of the simplest, and most completely treated, fields of application of quantum mechanics is the theory of atoms with one or two electrons For hydrogen and the analcgous ions He+, Li++, etc, the calculations can be performed exactly, both in Schrodinger’s nonrelativistic wave mechanics and in Dirac’s relativistic theory of the electron More specifically, the calculations are exact for a single electron in a fixed Coulomb potential Hydrogen-like atoms thus furnish an excellent way of testing the validity of quantum mechanics For such atoms the correction terms due to the motion and structure of atomic nuclei and due to quantum electrodynamic effects are small and can be calculated with high accuracy Since the energy levels of hydrogen and similar atoms can be investigated experimentally to an astounding degree of accuracy, some accurate tests of the validity of quantum electrodynamics are also possible Finally, the theory of such atoms in an external electric or magnetic field has also been developed in detail and compared with experiment
5,385 citations
TL;DR: In this article, the relativistic $S$-matrix formalism of Feynman is applied to the bound-state problem for two interacting Fermi-Dirac particles.
Abstract: The relativistic $S$-matrix formalism of Feynman is applied to the bound-state problem for two interacting Fermi-Dirac particles. The bound state is described by a wave function depending on separate times for each of the two particles. Two alternative integral equations for this wave function are derived with kernels in the form of an expansion in powers of ${g}^{2}$, the dimensionless coupling constant for the interaction. Each term in these expansions gives Lorentz-invariant equations. The validity and physical significance of these equations is discussed. In extreme nonrelativistic approximation and to lowest order in ${g}^{2}$ they reduce to the appropriate Schr\"odinger equation.One of these integral equations is applied to the deuteron ground state using scalar mesons of mass $\ensuremath{\mu}$ with scalar coupling. For neutral mesons the Lorentz-invariant interaction is transformed into the sum of the instantaneous Yukawa interaction and a retarded correction term. The value obtained for ${g}^{2}$ differs only by a fraction proportional to ${(\frac{\ensuremath{\mu}}{M})}^{2}$ from that obtained by using a phenomenological Yukawa potential. For a purely charged meson theory a correction term is obtained by a direct solution of the relativistic integral equation using only the first term in the expansion of the kernel. This correction is due to the fact that a nucleon can emit, or absorb, positive and negative mesons only alternately. The constant ${g}^{2}$ is increased by a fraction of $1.1(\frac{\ensuremath{\mu}}{M})$ or 15 percent.
1,962 citations
TL;DR: In this paper, the Bethe-Salpeter equation with one particle restricted to the mass shell is described, resulting in a three-dimensional covariant equation which can be easily interpreted physically.
Abstract: Integral equations suitable for the dynamical treatment of strongly interacting particles are derived. The equations can be described as Bethe-Salpeter equations with one particle restricted to the mass shell, resulting in a three-dimensional covariant equation which can be easily interpreted physically. To restore the dynamical terms omitted in the process of restricting one particle to the mass shell, additional kernels are added to the irreducible kernels from the original Bethe-Salpeter equation. The addition of these extra terms leads to a resulting simplification in the kernels themselves, since the new kernels have the same structure as the original ones, with some partial cancellations. Estimates as to the convergence of the procedure and the sizes of the various potentials are given. The special case of the hydrogen atom is discussed briefly, and comments are made on the application of these equations to the nuclear-force problem. Connections between scattering equations and bound-state equations are discussed, and the relativistic normalization condition for bound-state wave functions is derived.
281 citations
TL;DR: Positronium is a two-body, leptonic, particle-antiparticle system which possesses self-annihilation channels not directly present in any system studied to date as discussed by the authors.
Abstract: Positronium is a two-body, leptonic, particle-antiparticle system which possesses self-annihilation channels not directly present in any system studied to date. These features make it ideal for the study of the relativistic, two-body problem in quantum electrodynamics. This review will focus on recent experimental advances in fundamental positronium research. In addition, a less detailed discussion of recent theoretical advances is outlined. The review also contains a fairly detailed historial introduction and a section discussing uses of positronium in research not related to tests of quantum electrodynamics.
202 citations
TL;DR: In this article, the ground-state hyperfine-structure interval in positronium was determined based on extensive new data at low N 2 gas densities combined with previous data from Yale University.
Abstract: We report a new, more precise determination of the ground-state hyperfine-structure interval $\ensuremath{\Delta}\ensuremath{
u}$ in positronium, which is based on extensive new data at low ${\mathrm{N}}_{2}$-gas densities combined with previous data from our group at Yale University. Our experimental value $\ensuremath{\Delta}\ensuremath{
u}=203.38910(74)$ GHz (3.6 ppm) agrees with the current theoretical value $\ensuremath{\Delta}\ensuremath{
u}=203.400$ GHz, for which the estimated uncertainty is about 50 ppm.
121 citations