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 discuss a possible measurement of the ratio of the nucleon structure functions, F n 2 /F p 2 , and the ratio of up to down quark distributions, u/d, at large x, by performing deep inelastic electron scattering from the 3 H and 3 He mirror nuclei with the 11 GeV upgraded beam of Jefferson Lab. The measurement is expected to be almost free of nuclear effects, which introduce a significant uncertainty in the extraction of these two ratios from deep inelastic scattering off the proton and deuteron. The results are expected to test perturbative and non-perturbative mechanisms of spin-flavor symmetry breaking in the nucleon, and constrain the structure function parametrizations needed for the interpretation of high energy e-p, p-p and p-¯p collider data. The precision of the expected data can also allow for testing competing parametrizations of the nuclear EMC effect and provide valuable constraints on models of its dynamical origin.

Measurement of the F2n/F2p and d/u Ratios in Deep Inelastic Electron Scattering off 3H and 3He

We suggest that the Standard Model may undergo a supercritical transition near the Landau scale, where the U(1) gauge boson couples to the left and right handed states of any given fermion with different charges. This scenario naturally gives rise to three generations of fermion, corresponding to the three critical scales for the right-right, right-left and left-left fermion interactions going supercritical, as well as CP violation in the quark sector.

A New Hypothesis on the Origin of the Three Generations

The Charge-Symmetry-Breaking (CSB) character of the nucleon-nucleon interaction is well established. This work presents two different ways of introducing such effects into a nuclear Energy Density Functional (EDF). CSB terms are either coming from the effective theory expansion or are derived from electromagnetic mixing of $\rho^0$ and $\omega$ mesons. These terms are then introduced to Skyrme and Quark-Meson-Coupling EDFs, respectively.

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On introducing Charge-Symmetry-Breaking terms to nuclear Energy Density Functionals

Nuclear physics requires at least one major facility world-wide which is capable of fully exploiting the properties of the electro-weak force to investigate precisely the structure of strongly interacting systems. At its current maximum energy of 6 GeV Jefferson Lab has provided a wealth of important information on the structure of nucleons and nuclei. However, the plans to double the energy over the next seven years promise to open new frontiers in nuclear and particle physics. We briefly describe the plans for the 12 GeV Upgrade and the associated physics opportunities.

/pdf/future-scientific-opportunities-at-jefferson-lab-3kq2sj9nt2.pdf

Future scientific opportunities at jefferson lab

We review recent progress in our understanding of the role of strange quarks in the structure of the nucleon. For the contribution to its mass the result is remarkably small, an order of magnitude smaller than commonly assumed. This has profound consequences for the searches for dark matter which are currently underway. There has also been remarkable progress in the understanding of hypernuclei. In particular, there is a very natural explanation at the quark level of why Λ-hypernuclei are bound whereas Σ-hypernuclei are not. The consequences for dense matter, for example in neutron stars, are not yet fully understood but we know they are significant.

Anthony W. Thomas

Papers

Measurement of the F2n/F2p and d/u Ratios in Deep Inelastic Electron Scattering off 3H and 3He

A New Hypothesis on the Origin of the Three Generations

On introducing Charge-Symmetry-Breaking terms to nuclear Energy Density Functionals

Future scientific opportunities at jefferson lab

Importance of Strange Quarks in Hadrons, Nuclei and Dense Matter