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

Nuclear forces can be systematically derived using effective chiral Lagrangians consistent with the symmetries of QCD. I review the status of the calculations for two- and three-nucleon forces and their applications in few-nucleon systems. I also address issues like the quark mass dependence of the nuclear forces and resonance saturation for four-nucleon operators.

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Modern theory of nuclear forces

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.

/pdf/heavy-quarkonium-progress-puzzles-and-opportunities-2tru0l8jyp.pdf

Heavy quarkonium: progress, puzzles, and opportunities

http://cds.cern.ch/record/257993/files/9401310.pdf

QCD phenomenology based on a chiral effective Lagrangian

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

2+1 flavor QCD results of nuclear forces are reanalyzed by using a recently developed method which has a remarkable advantage that it can calculate nuclear forces without relying on the ground state saturation of Nambu-Bethe-Salpeter wave functions. Resulting potentials are parametrized by fit functions which mimic the functional form of AV18. These potentials are used to calculate the scattering phases.

2+1 flavor QCD results of nuclear forces

Description of baryons in the relativistic Faddeev approach to the NJL model

Lattice QCD calculations of baryon forces are performed for the first time with (almost) physical quark masses. = 2 + 1 dynamical clover fermion gauge configurations are generated at the lattice spacing of a \( \simeq \) 0.085 fm on a (96a)^4 \( \simeq \) (8.2 fm)^4 lattice with quark masses corresponding to (m_π,m_K) \( \simeq \) (146,525) MeV. Baryon forces are calculated using the time-dependent HAL QCD method. In this report, we study ΞΞ and NN systems both in ^1S_0 and ^3S_1–^3D_1 channels, and the results for the central and tensor forces as well as phase shifts in the ΞΞ (^1S_0) channel are presented.

Towards Lattice QCD Baryon Forces at the Physical Point: First Results

The penta-quark(5Q) Θ+(1540) is studied in anisotropic lattice QCD with renormalized anisotropy a s / a t = 4 for a high-precision measurement. Both the positive and the negative parity 5Q baryons are studied using a non-NK type interpolating field with I = 0 and J = 1 / 2 . After the chiral extrapolation, the lowest positive parity state is found at m Θ ≃ 2.25  GeV , which is too heavy to be identified with Θ+(1540). In the negative parity channel, the lowest energy state is found at m Θ ≃ 1.75  GeV . Although it is rather close to the empirical value, it is considered to be an NK scattering state rather than a localized resonance state.

Penta-Quark Anti-Decuplet in Anisotropic Lattice QCD

The WHOT-QCD Collaboration is pushing forward lattice studies of QCD at finite temperatures and densities using improved Wilson quarks. We first present results on QCD at zero and finite densities with two flavors of degenerate quarks (N_F=2 QCD) adopting the conventional fixed-Nt approach. We then report on the status of a study of N_F=2+1 QCD adopting a fixed-scale approach armed with the T-integration method which we have developed.

Noriyoshi Ishii

Papers

2+1 flavor QCD results of nuclear forces

Description of baryons in the relativistic Faddeev approach to the NJL model

Towards Lattice QCD Baryon Forces at the Physical Point: First Results

Penta-Quark Anti-Decuplet in Anisotropic Lattice QCD

QCD thermodynamics at zero and finite densities with improved Wilson quarks