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

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Statistical physics has proven to be a fruitful framework to describe phenomena outside the realm of traditional physics. Recent years have witnessed an attempt by physicists to study collective phenomena emerging from the interactions of individuals as elementary units in social structures. A wide list of topics are reviewed ranging from opinion and cultural and language dynamics to crowd behavior, hierarchy formation, human dynamics, and social spreading. The connections between these problems and other, more traditional, topics of statistical physics are highlighted. Comparison of model results with empirical data from social systems are also emphasized.

Statistical physics of social dynamics

We have studied the three quark system in a relativized version of the quark potential model with chromodynamics. With parameters consistent with those of an analogous study of meson spectroscopy we obtain a successful description of the spectrum of baryons. The model naturally explains the apparent absence of spin‐orbit interactions in baryons.

Baryons in a relativized quark model with chromodynamics

Monthly Notices is one of the three largest general primary astronomical research publications. It is an international journal, published by the Royal Astronomical Society. This article 1 describes its publication policy and practice.

Monthly Notices of the Royal Astronomical Society

We present a vision for the next decade of hadron physics in which the central question being addressed is how one might win new physical insight into the way hadronic systems work. The topics addressed include the relevance of model building, the role of spontaneously broken chiral symmetry, spectroscopy, form factors and physics in the deep inelastic regime.

/pdf/a-vision-of-hadronic-physics-2lgptskmrc.pdf

A vision of hadronic physics

We review various methods used to estimate uncertainties in quantum correlation functions, such as parton distribution functions (PDFs). Using a toy model of a PDF, we compare the uncertainty estimates yielded by the traditional Hessian and data resampling methods, as well as from explicitly Bayesian analyses using nested sampling or hybrid Markov chain Monte Carlo techniques. We investigate how uncertainty bands derived from neural network approaches depend on details of the network training, and how they compare to the uncertainties obtained from more traditional methods with a speciﬁc underlying parametrization. Our results show that utilizing a neural network on a simpliﬁed example of PDF data has the potential to inﬂate uncertainties, in part due to the cross validation procedure that is generally used to avoid overﬁtting data.

http://link.aps.org/pdf/10.1103/PhysRevD.106.036003

Determination of uncertainties in parton densities

We investigate the influence of the spatial extent of the proton magnetization and charge densities on the 2S hyperfine splitting in muonic hydrogen. The use of a non-perturbative relativistic Dirac approach leads to corrections of 15% to values obtained from the perturbative treatment encapsulated by the Zemach radius, which surpass the next-leading order contribution in the perturbation series by an order of magnitude.

Non-perturbative Analysis of the Influence of the Proton Magnetization and Charge Densities on the Hyperfine Splitting of Muonic Hydrogen

Chiral extrapolations will be essential for many years if one is to connect modern lattice QCD calculations with experiment. Given the enormous efforts made to ensure that the lattice QCD simulations are a rigorous implementation of nonperturbative QCD, it is essential that the chiral extrapolation procedure should also be consistent with all known constraints of QCD. We review the enormous progress made on this problem over the past three or four years.

Anthony W. Thomas

Papers

A vision of hadronic physics

Determination of uncertainties in parton densities

Non-perturbative Analysis of the Influence of the Proton Magnetization and Charge Densities on the Hyperfine Splitting of Muonic Hydrogen

Hadron structure and QCD: Effective field theory for lattice simulations

Lattice QCD calculations of hadron structure: Constituent quarks and chiral symmetry