Randy Lewis

Disconnected Loops with Twisted Mass Lattice QCD

Walter Wilcox, Dean Darnell, Ron Morgan +1

We give a general introduction and discussion of the issues involved in using the twisted mass formulation of lattice fermions in the context of disconnected loop calculations, inc…

A lattice QCD study of generalized gluelumps

Kristen Marsh, Randy Lewis

Proposals for physics beyond the standard model often include new colored particles at or beyond the scale of electroweak symmetry breaking. Any new particle with a sufficient life…

quant-ph2023

Quantum Computing for High-Energy Physics: State of the Art and Challenges. Summary of the QC4HEP Working Group

Alberto Di Meglio, Karl Jansen, Ivano Tavernelli +43

Quantum computers offer an intriguing path for a paradigmatic change of computing in the natural sciences and beyond, with the potential for achieving a so-called quantum advantage…

hep-ph2015

Low-energy constants and condensates from ALEPH hadronic $I ¨ $ decay data

Diogo Boito, Anthony Francis, Maarten Golterman +4

We determine the NLO chiral low-energy constant $L_{10}^{r}$ , and combinations $C_{12}^{r} \pm C_{61}^{r} + C_{80}^{r}$ , $C_{13}^{r} - C_{62}^{r} + C_{81}^{r}$ , $C_{61}^{r}$ , and $C_{87}^{r}$ , of the NNLO…

Lattice Computations of the Pion Form Factor

LHP Collaboration, Frederic D. R. Bonnet, Robert G. Edwards +3

We report on a program to compute the electromagnetic form factors of mesons. We discuss the techniques used to compute the pion form factor and present results computed with domai…

$I^\pm_{s}$ from the Lattice Hadronic Vacuum Polarisation

Renwick J. Hudspith, Randy Lewis, Kim Maltman +1

We present a determination of the QCD coupling constant, $I^\pm_{s}$ , obtained by fitting lattice results for the flavour $u d$ hadronic vacuum polarisation function to continuum perturb…

Strange quarks in quenched twisted mass lattice QCD

Abdou M. Abdel-Rehim, Randy Lewis, R. M. Woloshyn +1

Two twisted doublets, one containing the up and down quarks and the other containing the strange quark with an SU(2)-flavor partner, are used for studies in the meson sector. The r…

Lattice QCD with a twisted mass term and a strange quark

Abdou M. Abdel-Rehim, Randy Lewis, R. M. Woloshyn +1

There are three quarks with masses at or below the characteristic scale of QCD dynamics: up, down and strange. However, twisted mass lattice QCD relies on quark doublets. Various o…

quant-ph2025

The phase diagram of quantum chromodynamics in one dimension on a quantum computer

Anton T. Than, Yasar Y. Atas, Abhijit Chakraborty +8

The quantum chromodynamics (QCD) phase diagram, which reveals the state of strongly interacting matter at different temperatures and densities, is key to answering open questions i…

hep-ph2022

Substructure of Multiquark Hadrons (Snowmass 2021 White Paper)

Nora Brambilla, Hua-Xing Chen, Angelo Esposito +27

In recent years there has been a rapidly growing body of experimental evidence for existence of exotic, multiquark hadrons, i.e. mesons which contain additional quarks, beyond the…

hep-lat2012

Higher angular momentum states of bottomonium in lattice NRQCD

Randy Lewis, R. M. Woloshyn

On a cubic lattice the zero-momentum meson states have one of 20 possible Lambda^{PC} combinations where Lambda labels the irreducible representation of the octahedral group. Each…

hep-ph2018

Dark Matter from Strong Dynamics: The Minimal Theory of Dark Baryons

Anthony Francis, Renwick J. Hudspith, Randy Lewis +1

As a simple model for dark matter, we propose a QCD-like theory based on $SU (2)$ gauge theory with one flavor of dark quark. The model is confining at low energy and we use la…

hep-lat1998

O(1/M^3) effects for heavy-light mesons in lattice NRQCD

Randy Lewis, R. M. Woloshyn

The masses of spin-singlet and spin-triplet S-wave mesons containing a single heavy quark are computed in the quenched approximation. The light quark action and gauge field action…

hep-lat2011

Excited Upsilon Radiative Decays

Randy Lewis, R. M. Woloshyn

Bottomonium S-wave states were studied using lattice NRQCD. Masses of ground and excited states were calculated using multiexponential fitting to a set of correlation functions con…

hep-lat2010

Exploration of the phase structure of $S U (N_{c})$ lattice gauge theory with many Wilson fermions at strong coupling

Kei-ichi Nagai, Maria Georgina Carrillo-Ruiz, Gergana Koleva +1

We explore aspects of the phase structure of SU(2) and SU(3) lattice gauge theories at strong coupling with many flavours $N_{f}$ of Wilson fermions in the fundamental representation…

Fundamental Composite Higgs Dynamics on the Lattice: SU(2) with Two Flavors

Ari Hietanen, Randy Lewis, Claudio Pica +1

In reference [1] a unified description, both at the effective and fundamental Lagrangian level, of models of composite Higgs dynamics was proposed. In the unified framework the Hig…

hep-lat2013

Multi-boson spectrum of the SU(2)-Higgs model

Mark Wurtz, Randy Lewis

Lattice simulations are used to compute the spectrum of energy levels for all angular momentum and parity quantum numbers in the SU(2)-Higgs model, with parameters chosen to match…

hep-ph1994

Effects of technicolor on standard model running couplings

B. Holdom, Randy Lewis

We discuss the running couplings in the standard model, SU(3 $)_{C} \times$ SU(2 $)_{L} \times$ U(1 $)_{Y}$ , when the Higgs sector is replaced by SU( $N_{T C})$ technicolor. Particular attent…

Dark matter on the lattice

Randy Lewis

Several collaborations have recently performed lattice calculations aimed specifically at dark matter, including work with SU(2), SU(3), SU(4) and SO(4) gauge theories to represent…

Photon operators for lattice gauge theory

Randy Lewis, R. M. Woloshyn

Photon operators with the proper $J^{P C}$ quantum numbers are constructed, including one made of elementary plaquettes. In compact U(1) lattice gauge theory, these explicit photon…

hep-ph2002

The nucleon's strange electromagnetic and scalar matrix elements

Randy Lewis, W. Wilcox, R. M. Woloshyn

Quenched lattice QCD simulations and quenched chiral perturbation theory are used together for this study of strangeness in the nucleon. Dependences of the matrix elements on stran…

Hadron Spectroscopy with Lattice QCD

John Bulava, RaÃºl BriceÃ±o, William Detmold +13

The status and prospects for investigations of exotic and conventional hadrons with lattice QCD are discussed. The majority of hadrons decay strongly via one or multiple decay-chan…

Toward Group Theory Operators for tmLQCD Hadrons

Derek Harnett, Randy Lewis, Robert G. Petry

Extraction of the mass spectrum from twisted mass lattice QCD is facilitated by respecting the octahedral group of rotations and accommodating the broken parity and flavor symmetri…

Spectrum of quenched twisted mass lattice QCD at maximal twist

Abdou M. Abdel-Rehim, Randy Lewis, R. M. Woloshyn

Hadron masses are computed from quenched twisted mass lattice QCD for a degenerate doublet of up and down quarks with the twist angle set to pi/2, since this maximally twisted theo…

hep-lat1996

The rho meson decay constant using a tadpole-improved action

Randy Lewis, R. M. Woloshyn

The rho meson decay constant and the associated renormalization factor are computed in the quenched approximation on coarse lattices using a tadpole-improved action which is correc…

hep-lat2008

Exploring the meson spectrum with twisted mass lattice QCD

Robert G. Petry, Derek Harnett, Randy Lewis +1

Numerical simulations with access to all possible meson quantum numbers, J^{PC}, are presented using two-flavor (up and down) quenched twisted mass lattice QCD with three different…

The Spectrum of tmLQCD with Quark and Link Smearing

Abdou M. Abdel-Rehim, Randy Lewis, Robert G. Petry +1

The effect of using smeared sink operators on the hadron spectrum is studied for quenched twisted mass lattice QCD with up, down, and strange quarks. Gaussian smearing is used for…

hep-ph1999

Isospin Violation and the Proton's Strange Form Factors

Randy Lewis, Nader Mobed

The strange form factors of the proton are basic to an understanding of proton structure, and are presently the focus of many experiments. Before the strangeness effects can be ext…

nucl-th2006

Isospin breaking in the vector current of the nucleon

Randy Lewis

Extraction of the nucleon's strange form factors from experimental data requires a quantitative understanding of the unavoidable contamination from isospin violation. A number of a…

hep-lat2001

Spin splittings among charmed hadrons

Randy Lewis, Nilmani Mathur, R. M. Woloshyn

The mass differences between spin-1/2 and spin-3/2 baryons are compared to the mass differences between spin-0 and spin-1 mesons. Results of simulations for charmed hadrons in the…

hep-lat2025

False vacuum decay in triamond lattice gauge theory

Ali H. Z. Kavaki, Randy Lewis

The transition from a false vacuum to the true vacuum is a real-time phenomenon of interest in many contexts. It represents a special challenge for strongly interacting non-Abelian…

hep-lat2009

Effect of Multiple Higgs Fields on the Phase Structure of the SU(2)-Higgs Model

Mark Wurtz, Randy Lewis, T. G. Steele

The SU(2)-Higgs model, with a single Higgs field in the fundamental representation and a quartic self-interaction, has a Higgs region and a confinement region which are analyticall…

hep-ph2002

Baryon magnetic moments and sigma terms in lattice-regularized chiral perturbation theory

Bugra Borasoy, Randy Lewis, Pierre-Philippe A. Ouimet

An SU(3) chiral Lagrangian for the lightest decuplet of baryons is constructed on a discrete lattice of spacetime points, and is added to an existing lattice Lagrangian for the lig…

hep-lat2015

Determining the QCD coupling from lattice vacuum polarization

Renwick J. Hudspith, Randy Lewis, Kim Maltman +1

The QCD coupling appears in the perturbative expansion of the current-current two-point (vacuum polarization) function. Any lattice calculation of vacuum polarization is plagued by…

Lattice Results on the Connected Neutron Charge Radius

Alfred Tang, Walter Wilcox, Randy Lewis

We describe a calculation using quenched lattice QCD of the connected part of the neutron electric form factor for momentum transfers in the range $0.3 {\rm GeV^2} \stackrel{<}{\si…

hep-lat2007

Using evolutionary algorithms to extract field theory mass spectra

Georg M. von Hippel, Randy Lewis, Robert G. Petry

The spectrum of masses from a lattice QCD simulation may be found by fitting exponential functions to correlators of operators possessing the quantum numbers of the particles of in…

hep-lat2001

Heavy Baryons from Lattice NRQCD

Nilmani Mathur, Randy Lewis, R. M. Woloshyn

The mass spectrum of heavy quark baryons has been computed on anisotropic lattices using quenched lattice nonrelativistic QCD. The mass splittings between spin-1/2 and spin-3/2 bar…

hep-ph2001

Lattice regularization for chiral perturbation theory

Randy Lewis, Pierre-Philippe A. Ouimet

The SU(3) chiral lagrangian for the lightest octets of mesons and baryons is constructed on a spacetime lattice. The lattice spacing acts as an ultraviolet momentum cutoff which ap…

The pion electromagnetic form factor

Frederic D. R. Bonnet, Robert G. Edwards, George T. Fleming +2

A ratio of lattice correlation functions is identified from which the pion form factor can be obtained directly. Preliminary results from quenched Wilson simulations are presented.

hep-lat2024

From square plaquettes to triamond lattices for SU(2) gauge theory

Ali H. Z. Kavaki, Randy Lewis

Lattice gauge theory should be able to address significant new scientific questions when implemented on quantum computers. In practice, error-mitigation techniques have already all…

Pion form factor using domain wall valence and asqtad sea quarks

LHP Collaboration, George T. Fleming, Frederic D. R. Bonnet +3

We compute the pion electromagnetic form factor in a hybrid calculation with domain wall valence quarks and improved staggered (asqtad) sea quarks. This method can easily be extend…

hep-lat1998

S-wave charmed mesons in lattice NRQCD

Randy Lewis, R. M. Woloshyn

Heavy-light mesons can be studied using the 1/M expansion of NRQCD, provided the heavy quark mass is sufficiently large. Calculations of the S-wave charmed meson masses from a clas…

Mesonic Form Factors

LHPC Collaboration, Frederic D. R. Bonnet, Robert G. Edwards +3

We have started a program to compute the electromagnetic form factors of mesons. We discuss the techniques used to compute the pion form factor and present preliminary results comp…

hep-ph1994

Hadronic contribution to the photon vacuum polarization: a theoretical estimate

B. Holdom, Randy Lewis, Roberto R. Mendel

A simple model for the hadronic contribution to the photon vacuum polarization function $I^_{ha d} (q^{2})$ , for spacelike momenta, is presented. For small momenta, the two loop contri…

Self-mitigating Trotter circuits for SU(2) lattice gauge theory on a quantum computer

Sarmed A Rahman, Randy Lewis, Emanuele Mendicelli +1

Quantum computers offer the possibility to implement lattice gauge theory in Minkowski rather than Euclidean spacetime, thus allowing calculations of processes that evolve in real…

quant-ph2023

Simulating one-dimensional quantum chromodynamics on a quantum computer: Real-time evolutions of tetra- and pentaquarks

Yasar Y. Atas, Jan F. Haase, Jinglei Zhang +4

Quantum chromodynamics - the theory of quarks and gluons - has been known for decades, but it is yet to be fully understood. A recent example is the prediction and experimental dis…

nucl-th2006

Isospin violation in the vector form factors of the nucleon

Bastian Kubis, Randy Lewis

A quantitative understanding of isospin violation is an increasingly important ingredient for the extraction of the nucleon's strange vector form factors from experimental data. We…

Maximal twist and the spectrum of quenched twisted mass lattice QCD

Abdou M. Abdel-Rehim, Randy Lewis, R. M. Woloshyn

Results on the hadron masses for a degenerate doublet of up and down quarks from quenched twisted mass lattice QCD at maximal twist are presented. Two definitions of maximal twist…

The hadron spectrum from twisted mass QCD with a strange quark

Abdou M. Abdel-Rehim, Randy Lewis, R. M. Woloshyn

Various suggestions exist for incorporating the strange quark into twisted mass QCD. One option for quenched simulations is to employ two twisted doublets, (u,d) and (c,s), with se…

hep-lat2010

Bottom and charmed hadron spectroscopy from lattice QCD

Randy Lewis

A survey of recent lattice QCD simulations for the mass spectrum of bottom and charmed hadrons is presented.

hep-lat2009

Bottom baryons from a dynamical lattice QCD simulation

Randy Lewis, R. M. Woloshyn

Bottom baryon masses are calculated based on a 2+1 flavor dynamical lattice QCD simulation. The gauge field configurations were computed by the CP-PACS and JLQCD collaborations usi…

quant-ph2025

The charge-singlet measurement toolbox

Abhijit Chakraborty, Randy Lewis, Christine A. Muschik

Symmetry is fundamental to physical laws across different scales$\unicode{x2014}$from spacetime structure in general relativity to particle interactions in quantum field theory. Lo…

hep-ph2015

Low-energy constants from ALEPH hadronic tau decay data

Diogo Boito, Anthony Francis, Maarten Golterman +4

We determined the NLO chiral low-energy constant $L_{10}$ , and various combinations of NNLO chiral low-energy constants employing recently revised ALEPH results for the non-strange…

Lattice regularized chiral perturbation theory

Bugra Borasoy, Randy Lewis, Pierre-Philippe A. Ouimet

Chiral perturbation theory can be defined and regularized on a spacetime lattice. A few motivations are discussed here, and an explicit lattice Lagrangian is reviewed. A particular…

Novel $∣ V_{u s} ∣$ Determination Using Inclusive Strange $I ¨ $ Decay and Lattice HVPs

Peter Boyle, Renwick James Hudspith, Taku Izubuchi +7

We propose and apply a new approach to determining $∣ V_{u s} ∣$ using dispersion relations with weight functions having poles at Euclidean (space-like) momentum which relate strange…

hep-lat2007

Vacuum Expectation Values of Twisted Mass Fermion Operators

Abdou Abdel-Rehim, Randy Lewis, Walter Wilcox

Using noise methods on a quenched $2 0^{3} \times 32$ lattice at $I^^{2} = 6.0$ , we have investigated vacuum expectation values and relative linear correlations among the various Wilson and…

hep-ph2001

Charmed baryons in lattice QCD

Randy Lewis, Nilmani Mathur, R. M. Woloshyn

Masses of singly and doubly charmed baryons are calculated in quenched lattice QCD using an improved action of the D234 type on an anisotropic lattice. The mass differences between…

hep-lat2000

S and P-wave heavy-light mesons in lattice NRQCD

Randy Lewis, R. M. Woloshyn

The mass spectrum of S and P-wave mesons containing a single heavy quark is computed in the quenched approximation, using NRQCD up to third order in the inverse heavy quark mass ex…

quant-ph2021

SU(2) hadrons on a quantum computer

Yasar Atas, Jinglei Zhang, Randy Lewis +3

We realize, for the first time, a non-Abelian gauge theory with both gauge and matter fields on a quantum computer. This enables the observation of hadrons and the calculation of t…

hep-lat2019

A qubit model for U(1) lattice gauge theory

Randy Lewis, R. M. Woloshyn

A conceptually simple model for strongly interacting compact U(1) lattice gauge theory is expressed as operators acting on qubits. The number of independent gauge links is reduced…

Diquark properties from full QCD lattice simulations

Anthony Francis, Philippe de Forcrand, Randy Lewis +1

We study diquarks on the lattice in the background of a static quark, in a gauge-invariant formalism with quark masses down to almost physical $m_{I ¨} $ . We determine mass differences…

Free-form Smeared Bottomonium Correlation Functions

Mark Wurtz, Randy Lewis, R. M. Woloshyn

Gauge-invariant sources with a hydrogen wave function shape are constructed for bottomonium two-point correlation functions using the free-form smearing technique. The bottomonium…

hep-lat2010

Spontaneous symmetry breaking in a two-doublet lattice Higgs model

Randy Lewis, R. M. Woloshyn

An SU(2) lattice gauge theory with two doublets of complex scalar fields is considered. All continuous symmetries are identified and, using the nonperturbative methods of lattice f…

Composite (Goldstone) Higgs Dynamics on the Lattice: Spectrum of SU(2) Gauge Theory with two Fundamental Fermions

Rudy Arthur, Vincent Drach, Martin Hansen +4

We study the meson spectrum of the SU(2) gauge theory with two Wilson fermions in the fundamental representation. The theory unifies both Technicolor and composite Goldstone Boson…

hep-ph2012

It is a Graviton! or maybe not

Ricky Fok, Carol Guimaraes, Randy Lewis +1

The discovery of Kaluza-Klein (KK) gravitons is a smoking gun of extra dimensions. Other scenarios, however, could give rise to spin-two resonances of a new strongly-coupled sector…

Good and bad diquark properties and spatial correlations in lattice QCD

Anthony Francis, Philippe De Forcrand, Randy Lewis +1

We study good, bad and not-even-bad diquarks on the lattice in a gauge-invariant formalism in full QCD. We establish their spectral masses with short extrapolations to the physical…

hep-ph1995

Momentum dependent quark mass in two-point correlators

B. Holdom, Randy Lewis

A momentum dependent quark mass may be incorporated into a quark model in a manner consistent with dynamically broken chiral symmetry. We use this to study the high $Q^{2}$ behavior…

Twisted mass QCD for the pion electromagnetic form factor

Abdou M. Abdel-Rehim, Randy Lewis

The pion form factor is computed using quenched twisted mass QCD and the GMRES-DR matrix inverter. The momentum averaging procedure of Frezzotti and Rossi is used to remove leading…

hep-lat1996

Light vector meson decay constants and the renormalization factor from a tadpole-improved action

Randy Lewis, R. M. Woloshyn

The rho, K* and phi decay constants and the vector current renormalization factor are studied by using an O(a^2) classically-improved, tadpole-improved action. Tree-level calculati…

hep-ph2012

Light Asymmetric Dark Matter on the Lattice: SU(2) Technicolor with Two Fundamental Flavors

Randy Lewis, Claudio Pica, Francesco Sannino

The SU(2) gauge theory with two massless Dirac flavors constitutes the building block of several models of Technicolor. Furthermore it has also been used as a template for the cons…

Automated Methods in Chiral Perturbation Theory on the Lattice

Bugra Borasoy, Georg M. von Hippel, Hermann Krebs +1

We present a method to automatically derive the Feynman rules for mesonic chiral perturbation theory with a lattice regulator. The Feynman rules can be output both in a human-reada…

hep-ph2000

Charged radiative pion capture on the nucleon in heavy baryon chiral perturbation theory

Harold W. Fearing, Thomas R. Hemmert, Randy Lewis +1

The differential cross sections and s-wave and p-wave multipoles for $I ¨ ^{-} p \to I^^{3} n$ and $I ¨ ^{+} n \to I^^{3} p$ have been calculated through $O (p^{3})$ in heavy baryon chiral perturbation…

hep-ph2000

The charmed and bottom meson spectrum from lattice NRQCD

Randy Lewis, R. M. Woloshyn

The mass spectrum of S and P-wave mesons containing a single heavy quark has been computed using quenched lattice nonrelativistic QCD. Numerical results have been obtained at first…

Pion form factor with twisted mass QCD

Abdou M. Abdel-Rehim, Randy Lewis

The pion form factor is calculated using quenched twisted mass QCD with beta=6.0 and maximal twisting angle omega=pi/2. Two pion masses and several values of momentum transfer are…

hep-lat2017

Lattice Prediction for Deeply Bound Doubly Heavy Tetraquarks

Anthony Francis, Renwick J. Hudspith, Randy Lewis +1

We investigate the possibility of $q q^{'} b ˉ b ˉ$ tetraquark bound states using $n_{f} = 2 + 1$ lattice QCD ensembles with pion masses $≃ 164$ , $299$ , and $415$ MeV. Motiv…

Evidence for charm-bottom tetraquarks and the mass dependence of heavy-light tetraquark states from lattice QCD

Anthony Francis, Renwick J. Hudspith, Randy Lewis +1

We continue our study of heavy-light four-quark states and find evidence from lattice QCD for the existence of a strong-interaction-stable $I (J^{P}) = 0 (1^{+})$ $u d c ˉ b ˉ$ tetraq…

hep-lat2009

Exploration of SU(N_c) gauge theory with many Wilson fermions at strong coupling

Kei-ichi Nagai, Georgina Carrillo-Ruiz, Gergana Koleva +1

We explore aspects of the phase structure of SU(2) and SU(3) lattice gauge theories at strong coupling with many flavours $N_{f}$ of Wilson fermions in the fundamental representation…

hep-lat2016

Dark matter from one-flavor SU(2) gauge theory

Anthony Francis, Renwick James Hudspith, Randy Lewis +1

SU(2) gauge theory with a single fermion in the fundamental representation is a minimal non-Abelian candidate for the dark matter sector, which is presently missing from the standa…

hep-lat2015

Exploring free-form smearing for bottomonium and B meson spectroscopy

Mark Wurtz, Randy Lewis, R. M. Woloshyn

Free-form smearing was designed as a way to implement source operators of any desired shape. A variation of the method is introduced that reduces the computational cost by reducing…

hep-lat2013

Higgs and W boson spectrum from lattice simulations

Mark Wurtz, Randy Lewis

The spectrum of energy levels is computed for all available angular momentum and parity quantum numbers in the SU(2)-Higgs model, with parameters chosen to match experimental data…

hep-lat2002

Strange matrix elements of the nucleon

Randy Lewis, W. Wilcox, R. M. Woloshyn

Results for the disconnected contributions to matrix elements of the vector current and scalar density have been obtained for the nucleon from the Wilson action at beta=6 using a s…

hep-ph1997

Radiative and non radiative muon capture on the proton in heavy baryon chiral perturbation theory

Harold W. Fearing, Randy Lewis, Nader Mobed +1

We have evaluated the amplitude for muon capture by a proton, mu + p --> n + nu, to O(p^3) within the context of heavy baryon chiral perturbation theory (HBChPT) using the new O(p^…

hep-lat2017

More on heavy tetraquarks in lattice QCD at almost physical pion mass

Anthony Francis, Renwick J. Hudspith, Randy Lewis +1

We report on our progress in studying exotic, heavy tetraquark states, $q q' Q ˉ Q ˉ'$ . Using publicly available dynamical $n_{f} = 2 + 1$ Wilson-Clover gauge configuratio…

Finite volume effects using lattice chiral perturbation theory

Bugra Borasoy, Randy Lewis, Daniel Mazur

Lattice regularization is used to perform chiral perturbation theory calculations in finite volume. The lattice spacing is chosen small enough to be irrelevant, and numerical resul…

hep-lat2000

Heavy-light meson spectrum with and without NRQCD

Randy Lewis, R. M. Woloshyn

Results for the spectrum of S and P-wave charmed mesons are obtained in the quenched approximation from a tadpole-improved anisotropic gauge field action and a D234 quark action. T…

hep-lat2015

Free-form smearing for bottomonium and B meson spectroscopy

Mark Wurtz, Randy Lewis, R. M. Woloshyn

To obtain high-quality results from lattice QCD, it is important to use operators that produce good signals for the quantities of interest. Free-form smearing is a powerful tool th…

hep-ph1997

Muon capture by a proton in heavy baryon chiral perturbation theory

Harold W. Fearing, Randy Lewis, Nader Mobed +1

The matrix element for muon capture by a proton is calculated to O(p^3) within heavy baryon chiral perturbation theory using the new O(p^3) Lagrangian of Ecker and Mojzis. External…

hep-lat2007

Evolutionary Fitting Methods for the Extraction of Mass Spectra in Lattice Field Theory

Georg M. von Hippel, Randy Lewis, Robert G. Petry

We present an application of evolutionary algorithms to the curve-fitting problems commonly encountered when trying to extract particle masses from correlators in Lattice QCD. Harn…

hep-ph1998

Isospin violation and the proton's neutral weak magnetic form factor

Randy Lewis, Nader Mobed

The effects of isospin violation on the neutral weak magnetic form factor of the proton are studied using two-flavour chiral perturbation theory. The first nonzero contributions ap…

hep-lat2012

More about excited bottomonium radiative decays

Randy Lewis, R. M. Woloshyn

Radiative decays of bottomonium are revisited, focusing on contributions from higher-order relativistic effects. The leading relativistic correction to the magnetic spin-flip opera…

hep-ph2002

Charmed and Bottom Baryons from Lattice NRQCD

Nilmani Mathur, Randy Lewis, R. M. Woloshyn

The mass spectrum of charmed and bottom baryons has been computed on anisotropic lattices using quenched lattice nonrelativistic QCD. Masses are extracted by using mass splittings…

hep-lat2026

SU(2) gauge theory with fermions on a semi-simple cubic lattice

Randy Lewis, Shidsa Pourbakhsh, Arnab Pradhan +1

A practical Hamiltonian approach to lattice gauge theories would provide access to several important areas of phenomenology that have been beyond the reach of conventional lattice…