Publications (61)
An investigation into a wavelet accelerated gauge fixing algorithm
Terrence Draper, Craig McNeile
We introduce an acceleration algorithm for coulomb gauge fixing, using the compactly supported wavelets introduced by Daubechies. The algorithm is similar to Fourier acceleration.…
Improved Measure of Local Chirality
Terrence Draper, Andrei Alexandru, Ying Chen +7
It is popular to probe the structure of the QCD vacuum indirectly by studying individual fermion eigenmodes, because this provides a natural way to filter out UV fluctuations. The…
Strange Quark Magnetic Moment of the Nucleon at Physical Point
Raza Sabbir Sufian, Yi-Bo Yang, Andrei Alexandru +3
We report a lattice QCD calculation of the strange quark contribution to the nucleon's magnetic moment and charge radius. This analysis presents the first direct determination of s…
An Algorithm for Obtaining Reliable Priors for Constrained-Curve Fits
Terrence Draper, Shao-Jing Dong, Ivan Horvath +3
We introduce the ``Sequential Empirical Bayes Method'', an adaptive constrained-curve fitting procedure for extracting reliable priors. These are then used in standard augmented-ch…
and Pseudoscalar Form Factors from Lattice QCD
K. F. Liu, S. J. Dong, Terrence Draper +1
The form factor is obtained from a quenched lattice QCD calculation of the pseudoscalar form factor of the proton with pion pole dominance. We fin…
Proton mass decomposition
Yi-Bo Yang, Ying Chen, Terrence Draper +2
We report the results on the proton mass decomposition and also on the related quark and glue momentum fractions. The results are based on overlap valence fermions on four ensemble…
Status of Heavy Quark Physics on the Lattice
Terrence Draper
The status of lattice calculations of some phenomenology of heavy quarks is presented. Emphasis is on progress made in calculating those quantities relevant to estimating parameter…
N and strangeness sigma terms at the physical point with chiral fermions
Yi-Bo Yang, Andrei Alexandru, Terrence Draper +2
Lattice QCD calculations with chiral fermions of the N sigma term and strangeness sigma term including chiral interpolation with continuum and volume corre…
Nucleon isovector scalar charge from overlap fermions
Liuming Liu, Ting Chen, Terrence Draper +4
We calculate the nucleon isovector scalar charge in lattice QCD using overlap fermions on five ensembles of gauge configurations generated by the RBC/UKQCD collaboration using the…
Anatomy of the resonance from lattice QCD at the physical point
Wei Sun, Andrei Alexandru, Ying Chen +3
We propose a strategy to access the component of the resonance in lattice QCD. Through a mixed action formalism (overlap valence on domain wall sea), the energy of…
Muon g-2 with overlap valence fermions
Gen Wang, Terrence Draper, Keh-Fei Liu +1
We present a lattice calculation of the leading order (LO) hadronic vacuum polarization (HVP) contribution to the muon anomalous magnetic moment for the connected light and strange…
2+1 flavor QCD calculation of <x> and <x^2>
Devdatta Mankame, Takumi Doi, Terrence Draper +2
We calculate the connected insertions of the nucleon three-point function to study the first few moments of the unpolarized structure functions of the nucleon. (The disconnected in…
The Analysis of Space-Time Structure in QCD Vacuum II: Dynamics of Polarization and Absolute X-Distribution
Andrei Alexandru, Terrence Draper, Ivan Horvath +1
We propose a framework for quantitative evaluation of dynamical tendency for polarization in arbitrary random variable that can be decomposed into a pair of orthogonal subspaces. T…
Proton Mass Decomposition from the QCD Energy Momentum Tensor
Yi-Bo Yang, Jian Liang, Yu-Jiang Bi +4
We report results on the proton mass decomposition and also on related quark and glue momentum fractions. The results are based on overlap valence fermions on four ensembles of $N_…
Pion Form Factor with Overlap Fermion
Gen Wang, Jian Liang, Terrence Draper +2
We present a calculation of the pion form factor using overlap fermions on 2+1-flavor domain-wall configurations on a lattice with and on a $3…
Meson Matrix Elements from Various Heavy Quark Effective Theories
Terrence Draper, Craig McNeile
Various properties of heavy-light mesons are determined, including decay constants, the -parameter, and the Isgur-Wise function. The heavy (bottom) quark is simulated with t…
Glue Spin of the Proton
Yi-Bo Yang, Raza Sabbir Sufian, Andrei Alexandru +3
We report the progress on the lattice QCD calculation of the glue spin contribution to proton spin. This calculation is carried out with valence overlap fermion on 2+1 flavor DWF g…
Chiral Limit of Nucleon Lattice Electromagnetic Form Factors
Walter Wilcox, Terrence Draper, Keh-Fei Liu
We calculate electric and magnetic form factors of protons and neutrons in quenched Monte Carlo lattice QCD on a lattice at using Wilson fermions. We empl…
On the Locality and Scaling of Overlap Fermions at Coarse Lattice Spacings
Terrence Draper, Nilmani Mathur, Jianbo Zhang +7
The overlap fermion offers the considerable advantage of exact chiral symmetry on the lattice, but is numerically intensive. This can be made affordable while still providing large…
Nucleon Electric Dipole Moment from the Term with Lattice Chiral Fermions
Jian Liang, Andrei Alexandru, Terrence Draper +4
We calculate the nucleon electric dipole moment (EDM) from the term with overlap fermions on three domain wall lattices with different sea pion masses at lattice spacing 0.11…
Charm and strange quark masses and from overlap fermions
Yi-Bo Yang, Ying Chen, Andrei Alexandru +8
We use overlap fermions as valence quarks to calculate meson masses in a wide quark mass range on the -flavor domain-wall fermion gauge configurations generated by the RBC and…
Towards the nucleon hadronic tensor from lattice QCD
Jian Liang, Terrence Draper, Keh-Fei Liu +2
We present the first calculation of the hadronic tensor on the lattice for the nucleon. The hadronic tensor can be used to extract the structure functions in deep inelastic scatter…
Glue spin and helicity in proton from lattice QCD
Yi-Bo Yang, Raza Sabbir Sufian, Andrei Alexandru +4
We report the first lattice QCD calculation of the glue spin in the nucleon. The lattice calculation is carried out with valence overlap fermions on 2+1 flavor DWF gauge configurat…
Quark spins and Anomalous Ward Identity
Jian Liang, Yi-Bo Yang, Terrence Draper +2
We calculate the intrinsic quark spin contribution to the total proton spin using overlap valence quarks on three ensembles of -flavor RBC/UKQCD domain-wall configurations wit…
Stochastic method with low mode substitution for nucleon isovector matrix elements
Yi-Bo Yang, Andrei Alexandru, Terrence Draper +2
We introduce a stochastic sandwich method with low-mode substitution to evaluate the connected three-point functions. The isovector matrix elements of the nucleon for the axial-vec…
Meson Mass Decomposition
Yi-Bo Yang, Ying Chen, Terrence Draper +4
Hadron masses can be decomposed as a sum of components which are defined through hadronic matrix elements of QCD operators. The components consist of the quark mass term, the quark…
Quenched Chiral Behavior of Hadrons with Overlap Fermions
Shao-Jing Dong, Terrence Draper, Ivan Horvath +2
We study the quenched chiral behavior of hadrons with the pseudoscalar mass as low as MeV. We look for quenched chiral logs in the pion mass, determine the renormaliz…
A Study of the Static-Light Parameter
Joseph Christensen, Terrence Draper, Craig McNeile
We calculate the parameter, relevant for -- mixing, from a lattice gauge theory simulation using the static approximation for the heavy quark and the Wil…
Lattice Calculation of Nucleon Isovector Axial Charge with Improved Currents
Jian Liang, Yi-Bo Yang, Keh-Fei Liu +3
We employ dimension-4 operators to improve the local vector and axial-vector currents and calculate the nucleon isovector axial coupling with overlap valence on -flavo…
The Sequential Empirical Bayes Method: An Adaptive Constrained-Curve Fitting Algorithm for Lattice QCD
Ying Chen, Shao-Jing Dong, Terrence Draper +7
We introduce the ``Sequential Empirical Bayes Method'', an adaptive constrained-curve fitting procedure for extracting reliable priors. These are then used in standard augmented-$Ï…
Strange and Charm Quark Spins from Anomalous Ward Identity
Ming Gong, Yi-Bo Yang, Jian Liang +3
We present a calculation of the strange and charm quark contributions to the nucleon spin from the anomalous Ward identity (AWI). It is performed with overlap valence quarks on 2+1…
Baryon Octet to Decuplet Electromagnetic Transitions
Derek B. Leinweber, Terrence Draper, R. M. Woloshyn
The electromagnetic transition moments of the -flavor baryon octet to decuplet are examined within a lattice simulation of quenched QCD. The magnetic transition moment for t…
Variational calculation of heavy-light meson properties
Terrence Draper, Craig McNeile
We present a new method for the study of heavy-light mesons in the static approximation of lattice QCD which is optimally effective in isolating ground and excited states. With ``M…
The hadronic tensor from four-point functions on the lattice
Christian Zimmermann, Terrence Draper, Jian Liang +3
The hadronic tensor is the central non-perturbative object in the calculation of the cross section of lepton-hadron interactions like neutrino-nucleon scattering. It is usually par…
RI/MOM and RI/SMOM renormalization of quark bilinear operators using overlap fermions
Fangcheng He, Yu-Jiang Bi, Terrence Draper +3
We present the vector, scalar and tensor renormalization constants (RCs) using overlap fermions with either regularization independent momentum subtraction (RI/MOM) or symmetric mo…
Trace anomaly form factors from lattice QCD
Bigeng Wang, Fangcheng He, Gen Wang +4
The hadron mass can be obtained through the calculation of the trace of the energy-momentum tensor in the hadron which includes the trace anomaly and sigma terms. The anomaly due t…
Light scalar mesons in 2+1 flavor full QCD
Terrence Draper, Takumi Doi, Keh-Fei Liu +3
We study the a_0 and K_0^* light scalar mesons in 2+1 flavor full QCD. Particular attention is paid to fitting excited states, with an eye toward determining whether scattering sta…
Quenched Chiral Log and Light Quark Mass from Overlap Fermions
Terrence Draper, Shao-Jing Dong, Ivan Horvath +4
We study the quenched chiral behavior of the pion with mass as low as MeV. The calculation is done on a quenched lattice of size and fm with…
Nucleon strangeness form factors and moments of PDF
Takumi Doi, Mridupawan Deka, Shao-Jing Dong +5
The calculation of the nucleon strangeness form factors from N_f=2+1 clover fermion lattice QCD is presented. Disconnected insertions are evaluated using the Z(4) stochastic method…
Lattice HQET Calculation of the Isgur-Wise Function
Joseph Christensen, Terrence Draper, Craig McNeile
We calculate the Isgur-Wise function on the lattice, simulating the light quark with the Wilson action and the heavy quark with a direct lattice implementation of the heavy-quark e…
Elastic and resonance structures of the nucleon from hadronic tensor in lattice QCD: implications for neutrino-nucleon scattering and hadron physics
Jian Liang, Raza Sabbir Sufian, Bigeng Wang +5
We compute the Euclidean hadronic tensor from charge density operators and extract elastic and resonance structures by employing exponential fits to the four-point correlator, as w…
Lattice Calculation of Pion Form Factor with Overlap Fermions
Gen Wang, Jian Liang, Terrence Draper +2
We present a precise calculation of the pion form factor using overlap fermions on seven ensembles of 2+1-flavor domain-wall configurations with pion masses varying from 139 to 340…
Decuplet Baryon Structure from Lattice QCD
Derek B. Leinweber, Terrence Draper, R. M. Woloshyn
The electromagnetic properties of the SU(3)-flavor baryon decuplet are examined within a lattice simulation of quenched QCD. Electric charge radii, magnetic moments, and magnetic r…
Detecting the flavor content of the vacuum using the Dirac operator spectrum
Jian Liang, Andrei Alexandru, Yu-Jiang Bi +3
We compute the overlap Dirac spectrum on three gauge ensembles generated using -flavor domain wall fermions. The three ensembles have different lattice spacings and two of the…
Fast Fermion Smearing Scheme with Gaussian-like Profile
ChuanYang Li, Terrence Draper, Jun Hua +5
We propose a novel smearing scheme which gives a Gaussian-like profile and is more efficient than the traditional Gaussian smearing in terms of computer time consumption. We also c…
Proton momentum and angular momentum decompositions with overlap fermions
Gen Wang, Yi-Bo Yang, Jian Liang +2
We present a calculation of the proton momentum and angular momentum decompositions using overlap fermions on a -flavor RBC/UKQCD domain-wall lattice at 0.143 fm with a pion m…
Locality and Scaling of Quenched Overlap Fermions
Terrence Draper, Nilmani Mathur, Jianbo Zhang +6
The overlap fermion offers the tremendous advantage of exact chiral symmetry on the lattice, but is numerically intensive. This can be made affordable while still providing large l…
SU(3) lattice gauge autocorrelations with anisotropic action
Terrence Draper, Constantine Nenkov, Mike Peardon
We report results of autocorrelation measurements in pure lattice gauge theory. The computations are performed on the {\sc convex spp1200} parallel platform within the {\sc…
The calculation of nucleon strangeness form factors from N_f=2+1 clover fermion lattice QCD
Takumi Doi, Mridupawan Deka, Shao-Jing Dong +5
We study the strangeness electromagnetic form factors of the nucleon from the N_f=2+1 clover fermion lattice QCD calculation. The disconnected insertions are evaluated using the Z(…
Meson Mass Decomposition from Lattice QCD
Yi-Bo Yang, Ying Chen, Terrence Draper +4
Hadron masses can be decomposed as a sum of quark and glue components which are defined through hadronic matrix elements of QCD operators. The components consist of the quark mass…
Sea Quarks Contribution to the Nucleon Magnetic Moment and Charge Radius at the Physical Point
Raza Sabbir Sufian, Yi-Bo Yang, Jian Liang +2
We report a comprehensive analysis of the light and strange disconnected-sea quarks contribution to the nucleon magnetic moment, charge radius, and the electric and magnetic form f…
A calculation of the parameter in the static limit
Joseph Christensen, Terrence Draper, Craig McNeile
We calculate the parameter, relevant for -- mixing, from a lattice gauge theory simulation at . The bottom quarks are simulated in the stati…
Ratio of strange to momentum fraction in disconnected insertions
Jian Liang, Mingyang Sun, Yi-Bo Yang +2
The ratio of the strange quark momentum fraction to that of light quark or in disconnected insertions (DI) is calculated on the lattice with…
Strangeness and glue in the nucleon from lattice QCD
Takumi Doi, Mridupawan Deka, Shao-Jing Dong +5
We study the strangeness contribution to nucleon matrix elements using Nf=2+1 dynamical clover fermion configurations generated by the CP-PACS/JLQCD collaboration. In order to eval…
Absolute Measure of Local Chirality and the Chiral Polarization Scale of the QCD Vacuum
Andrei Alexandru, Terrence Draper, Ivan Horváth +1
The use of the absolute measure of local chirality is championed since it has a uniform distribution for randomly reshuffled chiral components so that any deviations from uniformit…
Nucleon strangeness form factors from N_f=2+1 clover fermion lattice QCD
Takumi Doi, Mridupawan Deka, Shao-Jing Dong +5
We present the N_f=2+1 clover fermion lattice QCD calculation of the nucleon strangeness form factors. We evaluate disconnected insertions using the Z(4) stochastic method, along w…
NRQCD and Static Systems -- A General Variational Approach
Terrence Draper, Craig McNeile, Constantine Nenkov
We present initial results from Monte Carlo simulations of NRQCD-light, static-light, and NRQCD-NRQCD mesons, using a variational technique (MOST), as part of our ongoing calculati…
The nucleon isovector tensor charge from lattice QCD using chiral fermions
Derek Horkel, Yujiang Bi, Martha Constantinou +5
In this work we present the isovector flavor combination for the nucleon tensor charge extracted from lattice QCD simulations using overlap fermions on domain-wall config…
Roper State from Overlap Fermions
Mingyang Sun, Ying Chen, Gen Wang +11
The Roper state is extracted with valence overlap fermions on a -flavor domain-wall fermion lattice (spacing fm and MeV) using both the Sequential Emp…
Renormalization of the Lattice HQET Isgur-Wise Function
Joseph Christensen, Terrence Draper, Craig McNeile
We compute the perturbative renormalization factors required to match to the continuum Isgur-Wise function, calculated using lattice Heavy Quark Effective Theory. The velocity, mas…
Constraints on charm-anticharm asymmetry in the nucleon from lattice QCD
Raza Sabbir Sufian, Tianbo Liu, Andrei Alexandru +6
We present the first lattice QCD calculation of the charm quark contribution to the nucleon electromagnetic form factors in the momentum transfer range $0\leq Q^2…