[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

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

The hidden-charm pentaquark and tetraquark states

A large number of experimental discoveries especially in the heavy quarkonium sector that did not at all fit to the expectations of the until then very successful quark model led to a renaissance of hadron spectroscopy Among various explanations of the internal structure of these excitations, hadronic molecules, being analogues of light nuclei, play a unique role since for those predictions can be made with controlled uncertainty We review experimental evidences of various candidates of hadronic molecules, and methods of identifying such structures Nonrelativistic effective field theories are the suitable framework for studying hadronic molecules, and are discussed in both the continuum and finite volumes Also pertinent lattice QCD results are presented Further, we discuss the production mechanisms and decays of hadronic molecules, and comment on the reliability of certain assertions often made in the literature

Hadronic molecules

We review how nuclear forces emerge from low-energy QCD via chiral effective field theory. The presentation is accessible to the non-specialist. At the same time, we also provide considerable detailed information (mostly in appendices) for the benefit of researchers who wish to start working in this field.

Chiral effective field theory and nuclear forces

The spectrum is studied in a generalized constituent quark model constrained in the study of the NN phenomenology and the baryon spectrum. An overall good fit to the available experimental data is obtained. A detailed analysis of all sectors from the light-pseudoscalar and vector mesons to bottomonium is performed paying special attention to the existence and nature of some non well-established states. These results should serve as a complementary tool in distinguishing conventional quark model mesons from glueballs, hybrids or multiquark states.

Constituent quark model study of the meson spectra

We review the application of non-relativistic constituent quark models to study one, two and three non-strange baryon systems. We present results for the baryon spectra, potentials and observables of the nucleon?nucleon (NN), N?, ?? and NN*(1440) systems, and binding energies of three non-strange baryon systems. We emphasize the observable effects related to quark antisymmetry and its interplay with quark dynamics.

https://iopscience.iop.org/article/10.1088/0034-4885/68/5/R01/pdf

Quark-model study of few-baryon systems

We have performed a coupled channel calculation of the ${1}^{++}$ $c\overline{c}$ sector including $q\overline{q}$ and $D{D}^{*}$ molecular configurations. The calculation was done within a constituent quark model which successfully describes the meson spectrum, in particular, the $c\overline{c}$ ${1}^{--}$ sector. Two and four-quark configurations are coupled using the $^{3}P_{0}$ model. The elusive $X(3872)$ meson appears as a new state with a high probability for the $D{D}^{*}$ molecular component. When the mass difference between neutral and charged states is included, a large ${D}^{0}{D}^{*0}$ component is found which dominates for large distances and breaks isospin symmetry in the physical state. The original $c\overline{c}(2^{3}P_{1})$ state acquires a sizable $D{D}^{*}$ component and can be identified with the $X(3940)$. We study the $B\ensuremath{\rightarrow}K{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}J/\ensuremath{\psi}$ and $B\ensuremath{\rightarrow}K{D}^{0}{D}^{*0}$ decays, finding a good agreement with Belle and BABAR experimental data.

Coupled channel approach to the structure of the X ( 3872 )

A modified quark-quark interaction is applied to study the nucleon-nucleon interaction. The quark potential is suggested by instanton models and includes pion ( pi ) and sigma ( sigma ) exchanges as non-perturbative components and the one-gluon exchange as a perturbative one. The nucleon-nucleon potential derived from this model presents short-range repulsion and medium-range attraction besides the usual pion tail. Using this interaction the nucleon-nucleon phase shifts within the resonating group method have been calculated. They agree reasonably well with experimental values.

http://iopscience.iop.org/article/10.1088/0954-3899/19/12/007/pdf

The nucleon-nucleon interaction in terms of quark degrees of freedom

The recent B factories measurements of new states exhibit, in most of the decays, charmonium-like resonances. Among them we study the ${J}^{PC}={1}^{--}$ hidden charm resonances in order to assert if they are $q\overline{q}$ states or more complicated structures. The energy spectrum, electromagnetic, and strong decays are studied in a constituent quark model which has been able to reproduce the hadronic phenomenology and the baryon-baryon interaction. Most of the reported states are nicely interpreted as $q\overline{q}$ pairs. The new $\ensuremath{\psi}(4360)$ state is found as the $4S$ state and the $\ensuremath{\psi}(4415)$ as the $3D$ which differs from the standard assignment. Some of the states, such as the $Y(4260)$, cannot be accommodated as $q\overline{q}$ pairs.

Francisco Fernández

Papers

Constituent quark model study of the meson spectra

Quark-model study of few-baryon systems

Coupled channel approach to the structure of the X ( 3872 )

The nucleon-nucleon interaction in terms of quark degrees of freedom

JPC=1-- hidden charm resonances