Anthony G. Williams

Birmingham Women’s and Children’s NHS Foundation Trust

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Derek B. Leinweber

University of Adelaide

187

A. W. Thomas

University of Adelaide

J. M. Zanotti

University of Adelaide

Waseem Kamleh

University of Adelaide

Patrick O. Bowman

University of Queensland

M. J. White

University of Adelaide

Ben Lasscock

Enthought (United States)

Lorenz von Smekal

University of Giessen

Wally Melnitchouk

Thomas Jefferson National Accelerator Facility

André Sternbeck

Friedrich Schiller University Jena

Cooperative Institutions

University of Adelaide

155

European Organization for Nuclear Research

A. Alikhanyan National Laboratory

Fermi National Accelerator Laboratory

Istituto Nazionale di Fisica Nucleare, Sezione di Roma I

ARC Centre of Excellence for Dark Matter Particle Physics

Institute of High Energy Physics

Centre National de la Recherche Scientifique

University of Melbourne

University of Antwerp

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Subtractive Renormalization of Strong-Coupling Quenched QED in Four Dimensions

WORLD SCIENTIFIC eBooks (1996)

Frederick T. Hawes Tom Sizer Anthony G. Williams

We study renormalized quenched strong-coupling QED in four dimensions in arbitrary covariant gauge, in the Dyson-Schwinger equation formalism. Above the chiral critical coupling, we show that there is no finite chiral limit. This behaviour is found to be independent of the detailed choice of proper vertex, provided that the vertex is consistent with the Ward-Takahashi identity and multiplicative renormalizability. The finite solutions previously reported lie in an unphysical regime of the theory with multiple solutions and oscillating mass functions. This study is consistent with the assertion that strong coupling QED$_4$ does not have a continuum limit in the conventional sense.

Vertex function

Formalism (music)

Source

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Analysis of rho-omega interference in the pion form-factor

Physics Letters B (1996)

Kim Maltman H.B. O’Connell Anthony G. Williams

Formalism (music)

10.1016/0370-2693(96)00293-6

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Citations (31)

Research in theoretical physics

D. Robson Anthony G. Williams

This report discusses: hamiltonian lattice gauge theory; relativistic potential model; chiral potential models; covariant dynamical chiral symmetry breaking models of hadronic structure; light-cone calculations and models; and strangeness in the nucleon. LSP

Hamiltonian (control theory)

Lattice (music)

Chiral model

10.2172/5005310

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Recoil imaging for directional detection of dark matter, neutrinos, and physics beyond the Standard Model

arXiv (Cornell University) (2022)

Ciaran A. J. O’Hare D. Loomba K. Altenmüller H. Álvarez-Pol F. D. Amaro

Recoil imaging entails the detection of spatially resolved ionization tracks generated by particle interactions. This is a highly sought-after capability in many classes of detector, with broad applications across particle and astroparticle physics. However, at low energies, where ionization signatures are small in size, recoil imaging only seems to be a practical goal for micro-pattern gas detectors. This white paper outlines the physics case for recoil imaging, and puts forward a decadal plan to advance towards the directional detection of low-energy recoils with sensitivity and resolution close to fundamental performance limits. The science case covered includes: the discovery of dark matter into the neutrino fog, directional detection of sub-MeV solar neutrinos, the precision study of coherent-elastic neutrino-nucleus scattering, the detection of solar axions, the measurement of the Migdal effect, X-ray polarimetry, and several other applied physics goals. We also outline the R&D programs necessary to test concepts that are crucial to advance detector performance towards their fundamental limit: single primary electron sensitivity with full 3D spatial resolution at the $\sim$100 micron-scale. These advancements include: the use of negative ion drift, electron counting with high-definition electronic readout, time projection chambers with optical readout, and the possibility for nuclear recoil tracking in high-density gases such as argon. We also discuss the readout and electronics systems needed to scale-up such detectors to the ton-scale and beyond.

Recoil

Astroparticle physics

10.48550/arxiv.2203.05914

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Precision electromagnetic structure of octet baryons in the chiral regime

Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D, Particles, fields, gravitation, and cosmology (2006)

S. Boinepalli Derek B. Leinweber Anthony G. Williams J. M. Zanotti J. B. Zhang

The electromagnetic properties of the baryon octet are calculated in quenched QCD on a 20^3 x 40 lattice with a lattice spacing of 0.128 fm using the fat-link irrelevant clover (FLIC) fermion action. FLIC fermions enable simulations to be performed efficiently at quark masses as low as 300 MeV. By combining FLIC fermions with an improved-conserved vector current, we ensure that discretisation errors occur only at O(a^2) while maintaining current conservation. Magnetic moments and electric and magnetic radii are extracted from the electric and magnetic form factors for each individual quark sector. From these, the corresponding baryon properties are constructed. Our results are compared extensively with the predictions of quenched chiral perturbation theory. We detect substantial curvature and environment sensitivity of the quark contributions to electric charge radii and magnetic moments in the low quark mass region. Furthermore, our quenched QCD simulation results are in accord with the leading non-analytic behaviour of quenched chiral perturbation theory, suggesting that the sum of higher-order terms makes only a small contribution to chiral curvature.

Charge radius

Octet

10.1103/physrevd.74.093005

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Citations (110)

Preface

Nuclear Physics B - Proceedings Supplements (2004)

Alexander C. Kalloniatis Derek B. Leinweber Anthony G. Williams

10.1016/s0920-5632(03)02450-2

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Dynamical chiral symmetry breaking and confinement with an infrared-vanishing gluon propagator?

Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields (1994)

Frederick T. Hawes Craig D. Roberts Anthony G. Williams

We study a model Dyson-Schwinger equation for the quark propagator closed using an Ansatz for the gluon propagator of the form D(q)\ensuremath{\sim}${\mathit{q}}^{2}$/[(${\mathit{q}}^{2}$${)}^{2}$+${\mathit{b}}^{4}$] and two Ansa$uml---tze for the quark-gluon vertex: the minimal Ball-Chiu form and the modified form suggested by Curtis and Pennington. Using the quark condensate as an order parameter, we find that there is a critical value of b=${\mathit{b}}_{\mathit{c}}$ such that the model does not support dynamical chiral symmetry breaking for b>${\mathit{b}}_{\mathit{c}}$. We discuss and apply a confinement test which suggests that, for all values of b, the quark propagator in the model is not confining. Together these results suggest that this Ansatz for the gluon propagator is inadequate as a model since it does not yield the expected behavior of QCD.

Propagator

Ansatz

Color confinement

10.1103/physrevd.49.4683

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Citations (72)

Lattice gauge theory studies of the gluon propagator

arXiv (Cornell University) (1998)

Derek B. Leinweber Jon-Ivar Skullerud Anthony G. Williams

The gluon propagator in Landau gauge is calculated in quenched QCD on a large (32^3X64) lattice at beta=6.0. In order to assess finite volume and finite lattice spacing artefacts, we also calculate the propagator on a smaller volume for two different values of the lattice spacing. New structure seen in the infrared region survives conservative cuts to the lattice data, and serves to exclude a number of models that have appeared in the literature.

Propagator

Lattice (music)

Lattice gauge theory

Lattice model (finance)

10.48550/arxiv.hep-lat/9808037

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Probing EWPT in 2HDM with future lepton colliders

International Journal of Modern Physics A (2022)

Wei Su Anthony G. Williams Mengchao Zhang

The electroweak phase transition can be made first order by extending the Standard Model (SM) Higgs sector with extra scalars. Here, we focus on the strong first-order electroweak phase transition (SFOEWPT) in the Type-II two Higgs doublet models (2HDMs). Through a parameter space scan, we find that SFOEWPT suggests upper limits on the masses of the heavy Higgs [Formula: see text], which is less than 1[Formula: see text]TeV. High-temperature expansion and Higgs vacuum uplifting are used for analytical understanding of our results. We find that sizeable loop corrections require [Formula: see text] to meet the SFOEWPT condition in the Type-II 2HDM. We also study the possibility of probing SFOEWPT at the one-loop level from Higgs and [Formula: see text]-pole precision measurements at future Higgs and [Formula: see text] factories.

Higgs sector

Two-Higgs-doublet model

10.1142/s0217751x22460083

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SEMINAR. ENERGY AND THE ENVIRONMENT-CLEAN POWER FOR THE FUTURE.

ICE Proceedings (1991)

Anthony G. Williams Mark Tooley Adam Warren Jake Whitehead Jennifer Collier

Keywords INFRASTRUCTURE POLICY GROUP, IPG ENERGY, ENVIRONMENT, POWER, GENERATION, CONSERVATION, CONSUMPTION, POLICIES, ELECTRICITY, WIND, TIDAL, FUEL... Show All

Clean energy

10.1680/iicep.1991.16198

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