다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

To say that this is the best book on the quantum theory of fields is no praise, since to my knowledge it is the only book on this subject But it is a very good and most useful book The original was written in German and appeared in 1942 This is a translation with some minor changes A few remarks have been added, concerning meson theory and nuclear forces, also footnotes referring to modern work in this field, and finally an appendix on the symmetrization of the energy momentum tensor according to Belinfante Quantum Theory of Fields Prof Gregor Wentzel Translated from the German by Charlotte Houtermans and J M Jauch Pp ix + 224, (New York and London: Interscience Publishers, Inc, 1949) 36s

Quantum Theory of Fields

We give a general introduction to quantum phase transitions in strongly-correlated electron systems. These transitions which occur at zero temperature when a non-thermal parameter $g$ like pressure, chemical composition or magnetic field is tuned to a critical value are characterized by a dynamic exponent $z$ related to the energy and length scales $\Delta$ and $\xi$. Simple arguments based on an expansion to first order in the effective interaction allow to define an upper-critical dimension $D_{C}=4$ (where $D=d+z$ and $d$ is the spatial dimension) below which mean-field description is no longer valid. We emphasize the role of pertubative renormalization group (RG) approaches and self-consistent renormalized spin fluctuation (SCR-SF) theories to understand the quantum-classical crossover in the vicinity of the quantum critical point with generalization to the Kondo effect in heavy-fermion systems. Finally we quote some recent inelastic neutron scattering experiments performed on heavy-fermions which lead to unusual scaling law in $\omega /T$ for the dynamical spin susceptibility revealing critical local modes beyond the itinerant magnetism scheme and mention new attempts to describe this local quantum critical point.

https://arxiv.org/pdf/cond-mat/0102119.pdf

Quantum Phase Transitions

The authors review the theory and phenomenology of instantons in quantum chromodynamics (QCD). After a general overview, they provide a pedagogical introduction to semiclassical methods in quantum mechanics and field theory. The main part of the review summarizes our understanding of the instanton liquid in QCD and the role of instantons in generating the spectrum of light hadrons. The authors also discuss properties of instantons at finite temperature and how instantons can provide a mechanism for the chiral phase transition. They give an overview of the role of instantons in some other models, in particular low-dimensional sigma models, electroweak theory, and supersymmetric QCD.

http://wonka.physics.ncsu.edu/~tmschaef/physics/RevModPhys_Instantons.pdf

Instantons in QCD

The hidden-charm pentaquark and tetraquark states

Earlier investigations showed local minima in the monopole-antimonopole potential in U(1) gauge theory on the lattice. In this paper we localize monopoles of Monte-Carlo configurations. A statistical analysis of localization measurements gives us the probability density which we compare with the potential found in [1]. We find the monopoles mainly located either in the center of three-dimensional cubes or on the interface between two cubes. This agrees with the position of minima and maxima of the monopole-antimonopole potential.

Distribution of Magnetic Monopoles within cubes in Compact QED

We study the phase structure of full QCD within the canonical ensemble with respect to triality in a lattice formulation. The procedure for the calculation of the effective potentials in this case is given. As an example we consider the three dimensional SU(2) gauge model at finite temperatures in the strong coupling region. The potential exhibits a deconfinement phase transition unlike the similar potential obtained in the grand canonical ensemble which demonstrates explicit Z(N) symmetry breaking at any temperature. Furthermore, we investigate the effective potential with the chiral condensate included. In contradiction to other authors, we find chiral symmetry restoration in all triality sectors. In the scheme with massless staggered fermions we observe chiral symmetry restoration accompanying a deconfinement phase transition of first order. Above the critical point, besides two Z(2) symmetric "deconfining" vacua there exists a metastable "confining" vacuum in a wide region of parameters. Such a picture could be interpreted as an indication on a mixed state of hadrons and quarks in the vicinity of the critical line.

Deconfinement in QCD with dynamical quarks

We discuss that the singularities appearing in Dirac's formulation of magnetic monopoles are due to the set of fields which he used and not due to the physical properties of magnetic monopoles. We explain in detail that we can find the same algebraic expressions and singularities for the affine connections on the sphere $S^2$, which Dirac found for the U(1) gauge field of magnetic monopoles. Since spheres have no singularities, it is obvious, that these singularities are due to the set of fields which are used to describe the geometry of $S^2$. As there are descriptions of the geometry of spheres without any singularities, we indicate that it would be preferable to use singularity free descriptions of magnetic and also electric monopoles.

Dirac monopoles and the importance of the usage of appropriate degrees of freedom

In current heavy ion experiments at BNL and CERN the main aim is to create a new state of matter, the quark-gluon plasma (QGP). For this search energy densities of 2–3 GeV/fm3 corresponding to a temperature of ∼150 MeV or a matter density of 5–10 times nuclear density are required. The concept of the experiments is that two Lorentz-contracted nuclei collide and partly penetrate each other producing strong color-electric fields leading to a creation of free quarks and gluons. During expansion and cooling this QGP is converted to hadron matter. Most of the numerical investigations of QCD thermodynamics on space-time lattices indicate that this process may undergo a first order phase transition.1 At such a transition both phases can coexist at the critical temperature in thermodynamic equilibrium.

Surface Energy and Chiral Interface of A Coexisting Quark-Hadron System

A dynamics of low-energy nuclear forces is investigated for low-energy electromagnetic and weak nuclear reactions with the deuteron in the Nambu-Jona-Lasinio model of light nuclei by example of the neutron-proton radiative capture (M1-capture) n + p -> D + photon, the photomagnetic disintegration of the deuteron photon + D -> n + p and weak reactions of astrophysical interest. These are the solar proton burning p + p -> D + positron + nu_e, the pep-process p + electron + p -> D + nu_e and the neutrino and anti-neutrino disintegration of the deuteron caused by charged nu_e + D -> electron + p + p, anti-nu_e + D -> positron + n + n and neutral nu_e(anti-nu_e) + D -> nu_e(ant-nu_e) + n + p weak currents.

Manfried Faber

Papers

Distribution of Magnetic Monopoles within cubes in Compact QED

Deconfinement in QCD with dynamical quarks

Dirac monopoles and the importance of the usage of appropriate degrees of freedom

Surface Energy and Chiral Interface of A Coexisting Quark-Hadron System

Dynamics of low-energy nuclear forces for electromagnetic and weak reactions with the deuteron in the Nambu-Jona-Lasinio model of light nuclei