Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

https://escholarship.org/content/qt2dj9p3h4/qt2dj9p3h4.pdf?t=pmi3bw

ENDF/B-VIII.0: The 8th Major Release of the Nuclear Reaction Data Library with CIELO-project Cross Sections, New Standards and Thermal Scattering Data

Mes premiers remtrciements trout aux auteurs des 206 communications th6matiquts et notes de projet, sans qui ces actes n'auraient 6videmment pas vu le jour. / Is oat contribu6 h la qualit6 scientifique et ,5 I'hmuog6t~6it6 pr6sentationntlle de leurs articles en refondant les versions iuitiales soumises an comit6 de programme, ea acceptant de suivre les r~gles de pr6sentation indiqu6es, et en nous envoyant parrots plusieurs versions am61ior6es surun point ou sur l'autrc.

/pdf/about-these-proceedings-4s0qpzq930.pdf

About these proceedings

Quantum chromodynamics (QCD), the generally accepted theory for strong interactions, describes the interactions between quarks and gluons. The strongly interacting particles that are seen in nature are hadrons, which are composites of quarks and gluons. Since QCD is a strongly coupled theory at distance scales that are characteristic of observable hadrons, there are no rigorous, first-principle methods to derive the spectrum and properties of the hadrons from the QCD Lagrangian, except for lattice QCD simulations that are not yet able to cope with all aspects of complex and short-lived states. Instead, a variety of “QCD inspired” phenomenological models have been proposed. Common features of these models are predictions for the existence of hadrons with substructures that are more complex than the standard quark-antiquark mesons and the three-quark baryons of the original quark model that provides a concise description of most of the low-mass hadrons. Recently, an assortment of candidates for nonstandard multiquark mesons, meson-gluon hybrids, and pentaquark baryons that contain heavy (charm or bottom) quarks has been discovered. Here the experimental evidence for these states is reviewed and some general comparisons of their measured properties with standard quark model expectations and predictions of various models for nonstandard hadrons are made. The conclusion is that the spectroscopy of all but the simplest hadrons is not yet understood.

https://link.aps.org/accepted/10.1103/RevModPhys.90.015003

Nonstandard heavy mesons and baryons: Experimental evidence

Ab initio no core shell model

We present a chiral constituent-quark model for light and strange baryons providing a unified description of their ground states and excitation spectra. The model relies on constituent quarks and Goldstone bosons arising as effective degrees of freedom of low-energy QCD from the spontaneous breaking of chiral symmetry. The spectra of the three-quark systems are obtained from a precise variational solution of a Schr\"odinger-type equation with a semirelativistic Hamiltonian. The theoretical predictions are found to be in close agreement with experiment.

Unified description of light- and strange-baryon spectra

Covariant nucleon electromagnetic form-factors from the Goldstone boson exchange quark model

We study the performance of some recent potential models suggested as effective interactions between constituent quarks. In particular, we address constituent quark models for baryons with hybrid $Q\ensuremath{-}Q$ interactions stemming from one-gluon plus meson exchanges. Upon recalculating two of such models we find them to fail in describing the $N$ and $\ensuremath{\Delta}$ spectra. Our calculations are based on accurate solutions of the three-quark systems in both a variational Schr\"odinger and a rigorous Faddeev approach. It is argued that hybrid $Q\ensuremath{-}Q$ interactions with a sizable one-gluon-exchange component encounter difficulties in describing baryon spectra due to the specific contributions from one-gluon and meson exchanges together. In contrast, a chiral constituent quark model with a $Q\ensuremath{-}Q$ interaction relying solely on Goldstone-boson exchange is capable of providing a unified description not only of the $N$ and $\ensuremath{\Delta}$ spectra but also of all strange baryons in good agreement with phenomenology.

Effective Q-Q interactions in constituent quark models

Light baryons in a constituent quark model with chiral dynamics

A separable representation of a boson-exchange nucleon-nucleon potential is constructed via the Ernst-Shakin-Thaler method. The resulting separable interactions provide for a satisfactory approximation of the on-shell as well as off-shell properties of the Bonn potential. Their form factors are composed of rational functions suitable for today's computer codes for few-body systems. First results obtained with these separable potentials for elastic nucleon-deuteron scattering are presented.

Willibald Plessas

Papers

Unified description of light- and strange-baryon spectra

Covariant nucleon electromagnetic form-factors from the Goldstone boson exchange quark model

Effective Q-Q interactions in constituent quark models

Light baryons in a constituent quark model with chiral dynamics

Separable representation of the Bonn nucleon-nucleon potential