DETAILED STUDY OF THE FEW NUCLEON SYSTEMS AT JEFFERSON LAB

In a new and detailed experimental program carried out at Jefferson Laboratory, the few nucleon systems has been studied via Electrodisintegration of Deuterium and the Helium nuclei. Interesting new results probing the high momentum structure have been studied via the (e,e'p) reaction using the two high resolution spectrometers in Hall A and various kinematic regions have been investigated. Detailed and precise information on the effective bound state momentum distributions have been measured for the first time up to missing momenta of 1 Gev/c in 3 He , exhibiting significant strength at these high momenta which the standard nuclear calculations fail to explain and could be an indication of the onset of non-nucleonic degrees of freedom. The continuum region in 3 He has also been investigated in great detail looking for nuclear correlations and quasi-deuteron strength. Response function separations have been carried out to extract details of the few body structure and relativistic dynamics. Measurements made so far on D and 4 He have focussed on specific kinematic regions and there are plans to extend them over kinematic ranges similar to the 3 He investigation.

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An event excess observed in the deeply bound region of the 12C (K−, p) missing-mass spectrum

Progress of Theoretical and Experimental Physics ◽

10.1093/ptep/ptaa139 ◽

2020 ◽

Vol 2020 (12) ◽

Author(s):

Yudai Ichikawa ◽

Junko Yamagata-Sekihara ◽

Jung Keun Ahn ◽

Yuya Akazawa ◽

Kanae Aoki ◽

...

Keyword(s):

Mass Spectrum ◽

Binding Energy ◽

Decay Channel ◽

Peak Shift ◽

Bound State ◽

Elastic Peak ◽

Missing Mass ◽

Decay Modes ◽

Kaon Momentum ◽

First Time

Abstract We have measured, for the first time, the inclusive missing-mass spectrum of the $^{12}$C$(K^-, p)$ reaction at an incident kaon momentum of 1.8 GeV/$c$ at the J-PARC K1.8 beamline. We observed a prominent quasi-elastic peak ($K^-p \rightarrow K^-p$) in this spectrum. In the quasi-elastic peak region, the effect of secondary interaction is apparently observed as a peak shift, and the peak exhibits a tail in the bound region. We compared the spectrum with a theoretical calculation based on the Green’s function method by assuming different values of the parameters for the $\bar{K}$–nucleus optical potential. We found that the spectrum shape in the binding-energy region $-300 \, \text{MeV} < B_{K} < 40$ MeV is best reproduced with the potential depths $V_0 = -80$ MeV (real part) and $W_0 = -40$ MeV (imaginary part). On the other hand, we observed a significant event excess in the deeply bound region around $B_{K} \sim 100$ MeV, where the major decay channel of $K^- NN \to \pi\Sigma N$ is energetically closed, and the non-mesonic decay modes ($K^- NN \to \Lambda N$ and $\Sigma N$) should mainly contribute. The enhancement is fitted well by a Breit–Wigner function with a kaon-binding energy of 90 MeV and width 100 MeV. A possible interpretation is a deeply bound state of a $Y^{*}$-nucleus system.

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From Center-Vortex Ensembles to the Confining Flux Tube

Universe ◽

10.3390/universe7080253 ◽

2021 ◽

Vol 7 (8) ◽

pp. 253

Author(s):

David R. Junior ◽

Luis E. Oxman ◽

Gustavo M. Simões

Keyword(s):

Degrees Of Freedom ◽

String Tension ◽

Effective Field ◽

Scaling Properties ◽

Flux Tubes ◽

Topological Solitons ◽

Yang Mills ◽

Center Vortex ◽

Asymptotic Scaling ◽

The Continuum

In this review, we discuss the present status of the description of confining flux tubes in SU(N) pure Yang–Mills theory in terms of ensembles of percolating center vortices. This is based on three main pillars: modeling in the continuum the ensemble components detected in the lattice, the derivation of effective field representations, and contrasting the associated properties with Monte Carlo lattice results. The integration of the present knowledge about these points is essential to get closer to a unified physical picture for confinement. Here, we shall emphasize the last advances, which point to the importance of including the non-oriented center-vortex component and non-Abelian degrees of freedom when modeling the center-vortex ensemble measure. These inputs are responsible for the emergence of topological solitons and the possibility of accommodating the asymptotic scaling properties of the confining string tension.

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Additive Manufacturing for Effective Smart Structures: The Idea of 6D Printing

Journal of Composites Science ◽

10.3390/jcs5050119 ◽

2021 ◽

Vol 5 (5) ◽

pp. 119

Author(s):

Stelios K. Georgantzinos ◽

Georgios I. Giannopoulos ◽

Panteleimon A. Bakalis

Keyword(s):

Additive Manufacturing ◽

Degrees Of Freedom ◽

Smart Structures ◽

Interaction Mechanism ◽

Modeling And Simulations ◽

Environmental Stimulus ◽

Material Component ◽

Design And Manufacturing ◽

First Time ◽

Printing Techniques

This paper aims to establish six-dimensional (6D) printing as a new branch of additive manufacturing investigating its benefits, advantages as well as possible limitations concerning the design and manufacturing of effective smart structures. The concept of 6D printing, to the authors’ best knowledge, is introduced for the first time. The new method combines the four-dimensional (4D) and five-dimensional (5D) printing techniques. This means that the printing process is going to use five degrees of freedom for creating the final object while the final produced material component will be a smart/intelligent one (i.e., will be capable of changing its shape or properties due to its interaction with an environmental stimulus). A 6D printed structure can be stronger and more effective than a corresponding 4D printed structure, can be manufactured using less material, can perform movements by being exposed to an external stimulus through an interaction mechanism, and it may learn how to reconfigure itself suitably, based on predictions via mathematical modeling and simulations.

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STATISTICAL ORIGIN OF SPECIAL AND DOUBLY SPECIAL RELATIVITY

International Journal of Modern Physics Conference Series ◽

10.1142/s201019451301163x ◽

2013 ◽

Vol 23 ◽

pp. 373-378

Author(s):

PETR JIZBA ◽

FABIO SCARDIGLI

Keyword(s):

Brownian Motion ◽

Special Relativity ◽

Coarse Graining ◽

Relativistic Motion ◽

Relativistic Dynamics ◽

Compton Wavelength ◽

Primitive Concept ◽

Short Scale ◽

Doubly Special Relativity ◽

First Time

We show how a Brownian motion on a short scale can originate a relativistic motion on scales larger than particle's Compton wavelength. Special relativity appears to be not a primitive concept, but rather it statistically emerges when a coarse graining average over distances of order, or longer than the Compton wavelength is taken. Our scheme accommodates easily also the doubly special relativistic dynamics. A previously unsuspected, common statistical origin of the two frameworks is brought to light for the first time.

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High Q-factor fano resonances driven by quasi bound state in the continuum based on all-dielectric metasurface

10.1117/12.2601907 ◽

2021 ◽

Author(s):

Ziang Gao ◽

Shilin Yu ◽

Yusen Wang ◽

Tonggang Zhao

Keyword(s):

Bound State ◽

Q Factor ◽

Fano Resonances ◽

High Q ◽

Dielectric Metasurface ◽

The Continuum ◽

Quasi Bound State

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Free Vibration Analysis of Two-Stage Planetary Gear With Friction

ASME 2018 Noise Control and Acoustics Division Session presented at INTERNOISE 2018 ◽

10.1115/ncad2018-6133 ◽

2018 ◽

Author(s):

Wei Liu ◽

Yunbo Yuan ◽

Tao He ◽

Donghua Wang

Keyword(s):

Free Vibration ◽

Degrees Of Freedom ◽

Sliding Friction ◽

Free Vibration Analysis ◽

Planetary Gear ◽

Two Stage ◽

Second Stage ◽

Torsional Coupling ◽

Coupling Dynamic ◽

First Time

Considering the effect of teeth surface sliding friction, free vibration of two-stage planetary gears (TPG) is studied theoretically for the first time. The lateral-torsional coupling dynamic model and equation are established with three degrees of freedom: two translations and one rotation. The change rule of natural frequency is discussed with the case of first stage planetary gear’s number 4 and second stage planetary gear’s number 3, 4 and 5. Afterwards three vibration modes are summarized by calculating the free vibration. In order to understand the behavior of friction, the effect of friction on natural frequencies is analyzed for the case of considering friction and not considering friction. Furthermore, the ‘self-coupling’ phenomenon is obtained from the vibration of center component of TPG Meanwhile, the ‘mutual coupling’ is obtained between the first-stage planetary gear (FPG) and the second-stage planetary gear (SPG).

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