Utilising optimised operators and distillation to extract scattering phase shifts

In this investigation, we examine how the precision of energy spectra and scattering phase shifts, extracted in lattice QCD, depend upon the degree of distillation type smearing. We use the variational method to extract energy spectra for the isospin-1, J$^{PC}$ = 1$^{−−}$ channel and use the Lüscher method to compute scattering amplitudes, relevant for the ρ resonance, in ππ elastic scattering. Optimised interpolating operators for a single ground state pion are constructed and these are used to construct two pion operators. Calculations are performed on an anisotropic lattice with a pion mass of m$_{π}$ = 236MeV. We provide a comprehensive comparison of energy spectra and scattering phase shifts across distillation spaces of varying rank.AW is supported by the U.K. Science and Technology Facilities Council (STFC). CET acknowledges support from STFC [grant ST/L000385/1]. Computations were performed at Jefferson Laboratory under the USQCD Initiative and the LQCD ARRA project. The software codes Chroma, QUDA, QPhiX, and QOPQDP were used to compute the propagators required for this project. This research was supported in part under an ALCC award, and used resources of the Oak Ridge Leadership Computing Facility at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC05-00OR22725. This research is also part of the Blue Waters sustained-petascale computing project, which is supported by the National Science Foundation (awards OCI-0725070 and ACI-1238993) and the state of Illinois. Blue Waters is a joint effort of the University of Illinois at Urbana-Champaign and its National Center for Supercomputing Applications. This work is also part of the PRAC “Lattice QCD on Blue Waters”. This research used resources of the National Energy Research Scientific Computing Center (NERSC), a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DEAC02-05CH11231. The authors acknowledge the Texas Advanced Computing Center (TACC) at The University of Texas at Austin for providing HPC resources that have contributed to the research results reported within this paper. Gauge configurations were generated using resources awarded from the U.S. Department of Energy INCITE program at the Oak Ridge Leadership Computing Facility, the NERSC, the NSF Teragrid at the TACC and the Pittsburgh Supercomputer Center, as well as at Jefferson Lab

High-speed measurement of rotational anisotropy nonlinear optical harmonic generation using position sensitive detection

We present a method of performing high-speed rotational anisotropy nonlinear optical harmonic generation experiments at rotational frequencies of several hertz by projecting the harmonic light reflected at different angles from a sample onto a stationary position sensitive detector. The high rotational speed of the technique, $10^3$ to $10^4$ times larger than existing methods, permits precise measurements of the crystallographic and electronic symmetries of samples by averaging over low frequency laser power, beam pointing, and pulse width fluctuations. We demonstrate the sensitivity of our technique by resolving the bulk four-fold rotational symmetry of GaAs about its [001] axis using second harmonic generation

Efficient solution of the multichannel Lüscher determinant condition through eigenvalue decomposition

We present a method for efficiently finding solutions of L\"uscher's quantisation condition, the equation which relates two-particle scattering amplitudes to the discrete spectrum of states in a periodic spatial volume of finite extent such as that present in lattice QCD. The approach proposed is based on an eigenvalue decomposition in the space of coupled-channels and partial-waves, which proves to have several desirable and simplifying features that are of great benefit when considering problems beyond simple elastic scattering of spinless particles. We illustrate the method with a toy model of vector-vector scattering featuring a high density of solutions, and with an application to explicit lattice QCD energy level data describing $J^P=1^-$ and $1^+$ scattering in several coupled channels

WTO法与投资仲裁之合法性：缔约国的职责

International investment protection standards are the result of a “dilatory formula compromise,” i.e. a formal compromise without agreement on its precise content, due to historical reasons. Their development is mainly through arbitral awards and scholarly writings in the absence of the further involvement of the contracting parties, which raises legitimacy issues

Proposta de normalização da gestão de sinistros, na relação entre hospitais e fornecedores de seguros de saúde

Trabalho de projeto apresentado à Escola Superior de Comunicação Social como parte dos requisitos para obtenção de grau de mestre em Audiovisual e Multimédia.No início do estudo da interação homem-máquina, a noção de que sistemas de computador e software deveriam ser projetados e desenvolvidos em consideração às necessidades, habilidades e preferências de seus utilizadores não era uma visão dominante. Atualmente, porém, os estudos mostraram que em um processo de desenvolvimento de sistema ou interface o impulsionador das decisões de criação e alteração devem ser os utilizadores. A usabilidade passou a ser o objetivo a alcançar. E com este objetivo fixado os sistemas de suporte de fluxo de trabalho tornaram-se comuns. Este trabalho é uma proposta que atende a esta realidade e, por preocupar-se com a usabilidade e a otimização do fluxo de trabalho, propõe a normalização dos sistemas de faturação dos seguros de saúde. O projeto pretende ser uma proposta para a interface deste sistema uniformizado, baseando-se na crença de que a indústria de faturamento de saúde é capaz de tornar-se significativamente mais eficiente ao reduzir a necessidade de intervenção humana e o recurso a processos em papel, melhorando a consistência da codificação, e que com isso irá aumentar o rendimento e diminuir o tempo de pagamento e reembolso de serviços.ABSTRACT: Early in the study of human-computer interaction, the notion that computer and software systems should be designed and developed in consideration of the needs, abilities and preferences of their users was not a dominant view. Now, however, studies have shown that in a system development process or the driver of interface design decisions and changes should be the users. The usability has become the goal to reach. And with this aim set workflow support systems have become common. This work is a proposal that meets this reality and, focusing on the usability and workflow optimization, proposes the standardization of billing systems of health insurance. The project is intended as a theoretical proposal of how to be the interface of this uniform system, based on the belief that healthcare billing industry is able to become significantly more efficient by reducing the need for human intervention and the use of paper based processes, improving the consistency of coding, and with it will increase revenue and decrease the time of payment and reimbursement of services

Development of Peptide Based E3 Ligase Reporter

This dissertation describes the development of a new analytical tool capable of analyzing E3 ligase activity, a critical element in the ubiquitin proteasome system. This was accomplished through the development of a novel class of peptide-based fluorescent E3 ligase reporters which are intended to be analyzed by capillary electrophoresis (CE). These E3 ligase reporters incorporate a degradation signal, or degron, which is recognized and ubiquitinated by an E3 ligase, as well as a fluorescent tag to facilitate detection by laser induced fluorescence (LIF). In order to identify potent degrons, a library of E3 ligase reporters incorporating degrons from various sources was synthesized. These reporters were characterized in cell lysates, then optimized to produce substrates that would be efficiently ubiquitinated in cells. In addition to working with minimal degron sequences, an expanded sub-library of reporters based around the degron isolated from p53 was characterized in order to identify a compact degron element and investigate its ubiquitination kinetics and specificity. In order to circumvent peptidase-mediated degradation, a traditional weakness of peptide reporters, investigations were also carried out to develop novel degradation-resistant E3 ligase reporters incorporating β-hairpin secondary structures. Serendipitously, a β-hairpin that was both peptidase-resistant and functioned as an E3 ligase reporter was identified. Finally, electrophoretic separation conditions for the analysis of E3 ligase peptide reporters were identified, and ubiquitination of E3 ligase reporters in cell lysates was observed by CE-LIF. This dissertation lays the groundwork for future development of next generation peptide-based E3 ligase reporters.Doctor of Philosoph

The scattering of spinning hadrons from lattice QCD

Hadron spectroscopy is predominantly the study of resonances that decay via the strong interaction into a multitude of stable hadrons, such as the pion. The vast majority of resonances decay via an intermediate hadron with non-zero intrinsic spin. In this thesis, I will present the results of scattering calculations featuring mesons with non-zero intrinsic spin. Before doing so, I will first give a brief introduction to QCD and review the framework necessary to perform lattice QCD calculations in Chapters 1 and 2. In Chapter 3, I present the first lattice calculation of $\rho \pi$ scattering in isospin-2. Here, $\rho\pi$ features in dynamically-coupled $^3{S}_1$ and $^3{D}_1$ partial-waves with $J^P=1^+$. No resonance enhancement is anticipated in the flavour exotic isospin-2 channel and as such it provides an ideal testing ground for this first calculation. I work at heavier than physical quark masses at the $\text{SU}(3)_{\text{F}}$ point where the up, down and strange quarks are mass degenerate. Finite-volume spectra are calculated and, utilising the relationship between the discrete energy spectrum and the infinite-volume scattering amplitudes, partial-wave amplitudes with $J \le 3$ and the degree of dynamical mixing between the coupled $^3{S}_1$ and $^3{D}_1$ channels are determined. In Chapter 4, I investigate $\rho\pi$ in isospin-1 where the $a_1$ axial-vector resonance is expected to feature. Here, I present a discussion on $G$-parity and Bose-symmetry at the $\text{SU}(3)_{\text{F}}$ point. Working at heavier than physical quark masses, the resulting finite volume spectrum suggests that the $a_1$ is a bound-state and that the $^3{S}_1$- and $^3{D}_1$-wave, $\rho\pi$ scattering amplitudes are similar to those in isospin-2. I present the first calculation of coupled $\pi\omega$ and $\pi\phi$ scattering in Chapter 5 where resonant enhancement is seen experimentally in the $J^P=1^+$ channel. Working at a somewhat lighter pion mass than in previous chapters, the finite-volume spectra are determined and the scattering amplitudes are calculated. Analytically continuing the amplitudes into the complex energy plane, a resonance pole is found, interpreted as the analogue of the $b_1$ axial-vector, which couples dominantly to $^3{S}_1$-wave $\pi\omega$, with a much-suppressed coupling to $^3{D}_1$-wave $\pi\omega$, and a negligible coupling to $\pi\phi$. In Chapter 6, the exotic $J^{PC}=1^{-+}$ channel is studied. These quantum numbers are not allowed in the quark model but can be obtained, for example, through a gluonic excitation coupled to a quark-antiquark pair. In this exploratory calculation, performed at the $\text{SU}(3)_\text{F}$ point, the finite-volume spectra and coupled-channel scattering amplitudes are presented. A single resonance pole is found, interpreted as the exotic $\pi_1$, and couplings to meson-meson channels, including for example $\pi\eta\{^1{P}_1\}$, $\pi\eta'\{^1{P}_1\}$ and $\rho\pi\{^3{P}_1\}$, are calculated for the first time in lattice QCD. In order to minimally present the contents of a unitary $n$-channel scattering matrix, I introduce, in Chapter 7, an $n$-channel generalisation of the traditional two-channel Stapp parameterisation