723 citations · 7.8k across the 249 of their papers we have counts for
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Bjorken sum rule down to the elastic region from the lattice
J. A. Crawford, A. Hannaford-Gunn, R. Horsley +6
We present a lattice determination of the Bjorken sum rule via a Feynman-Hellmann calculation of the polarised forward Compton amplitude. We evaluate the lowest moment of the nucle…
Improving the electromagnetic form factor of the pion at large using the Feynman-Hellmann theorem
K. U. Can, J. A. Crawford, R. Horsley +7
At large momentum transfer, it becomes increasingly difficult to access the form factor of the pion using lattice QCD simulations. Two of the limiting factors include th…
Towards nucleon structure function moments and parton momentum fractions from lattice QCD
K. U. Can, R. Horsley, P. E. L. Rakow +4
We calculate the lowest even isovector moment of the structure function in -flavour lattice QCD with varying quark masses corresponding to $m_π\approx [410, 360, 300] \;…
Multi-nucleon matrix elements on the lattice with the Feynman-Hellmann theorem
N. Humphrey, K. U. Can, R. Horsley +5
This work presents the first calculation of the lowest moment of the forward Compton structure function for a multi-nucleon deuteron-like state using Feynman-Hellma…
Fourier Accelerated HMC in the SU(N) X SU(N) Principal Chiral Model
Roger Horsley, Pablo Morande, Brian Pendleton
We report the results of Fourier-accelerated HMC simulations of 2D SU(N) X SU(N) principal chiral models for N = 2, 3, 4, 6, 9. These models share several key properties with 4D QC…
Gross-Llewellyn Smith sum rule from lattice QCD
K. Utku Can, Joshua A. Crawford, Roger Horsley +6
We compute the Gross-Llewellyn Smith sum rule, i.e. the lowest odd moment of the parity-violating structure function, , of the nucleon from a lattice QCD calculation of the Co…
Transverse force distributions in the proton from lattice QCD
K. U. Can, J. A. Crawford, R. Horsley +5
Single-spin asymmetries observed in polarised deep-inelastic scattering are important probes of hadron structure. The Sivers asymmetry provides information about the transverse mom…
Renormalisation Group Equations for 2+1 clover fermions
K. U. Can, R. Horsley, P. E. L. Rakow +4
Many lattice QCD simulations now have many lattice spacings available, and it is of interest to investigate how they scale. In this talk we first derive renormalisation group equat…
Lattice QCD calculation of the Compton amplitude subtraction function
K. U. Can, A. Hannaford-Gunn, R. Horsley +6
The Compton amplitude subtraction function is an essential component in work concerning both the proton radius puzzle and the proton-neutron mass difference. However, owing to the…
Transverse force distributions in the proton from lattice QCD
J. A. Crawford, K. U. Can, R. Horsley +5
Single-spin asymmetries observed in polarised deep-inelastic scattering are important probes of hadron structure. The Sivers asymmetry has been the focus of much attention in QCD p…
Reconstructing generalised parton distributions from the lattice off-forward Compton amplitude
A. Hannaford-Gunn, K. U. Can, J. A. Crawford +6
We present a determination of the structure functions of the off-forward Compton amplitude and from the Feynman-Hellmann method in lattice QCD. At l…
The parity-odd structure function of nucleon from the Compton amplitude
K. U. Can, R. Horsley, Y. Nakamura +5
The dominant contribution to the theoretical uncertainty in the extracted weak parameters of the Standard Model comes from the hadronic uncertainties in the electroweak boxes, i.e.…
Hybrid Monte Carlo Simulation with Fourier Acceleration of the Principal Chiral Model in two Dimensions
Roger Horsley, Brian Pendleton, Julian Wack
Motivated by the similarity to QCD, specifically the property of asymptotic freedom, we simulate the dynamics of the SU(2) SU(2) model in two dimensions using the Hybrid M…
The Compton amplitude and nucleon structure functions in lattice QCD
K. U. Can, M. Batelaan, A. Hannaford-Gunn +8
The structure of hadrons relevant for deep-inelastic scattering are completely characterised by the Compton amplitude. A direct calculation of the Compton amplitude in a lattice QC…
Feynman--Hellmann approach to transition matrix elements and quasi-degenerate energy states
M. Batelaan, K. U. Can, R. Horsley +6
The Feynman--Hellmann approach to computing matrix elements in lattice QCD by first adding a perturbing operator to the action is described using the transition matrix and the Dyso…
Weak decay constants of the neutral pseudoscalar mesons from lattice QCD+QED
Z. R. Kordov, R. Horsley, W. Kamleh +7
With increasing requirements for greater precision, it becomes essential to describe the effects of isospin breaking induced by both quark masses and electro-magnetic effects. In t…
Constraining beyond the Standard Model nucleon isovector charges
R. E. Smail, M. Batelaan, R. Horsley +8
At the TeV scale, low-energy precision observations of neutron characteristics provide unique probes of novel physics. Precision studies of neutron decay observables are susceptibl…
Quasi-degenerate baryon energy states, the Feynman--Hellmann theorem and transition matrix elements
M. Batelaan, K. U. Can, R. Horsley +7
The standard method for determining matrix elements in lattice QCD requires the computation of three-point correlation functions. This has the disadvantage of requiring two large t…
Moments and power corrections of longitudinal and transverse proton structure functions from lattice QCD
M. Batelaan, K. U. Can, A. Hannaford-Gunn +8
We present a simultaneous extraction of the moments of and structure functions of the proton for a range of photon virtuality, . This is achieved by computing the…
Investigating the Compton amplitude subtraction function in lattice QCD
Alec Hannaford-Gunn, Edward Sankey, Kadir Utku Can +8
Theoretical predictions of the proton--neutron mass difference and measurements of the proton's charge radius require inputs from the Compton amplitude subtraction function. Model-…
Generalised Parton Distributions from Lattice Feynman-Hellmann Techniques
Alec Hannaford-Gunn, Kadir Utku Can, Roger Horsley +6
We report on the use of Feynman-Hellmann techniques to calculate the off-forward Compton amplitude (OFCA) in lattice QCD. At leading-twist, the Euclidean OFCA is parameterised by t…
Nucleon Form Factors from the Feynman-Hellmann Method in Lattice QCD
M. Batelaan, R. Horsley, Y. Nakamura +7
Lattice QCD calculations of the nucleon electromagnetic form factors are of interest at both the high and low momentum transfer regions. For high momentum transfers especially ther…
Measurements of symmetry breaking in meson decay constants
S. A. De La Motte, S. E. Hollitt, R. Horsley +9
We present updates from QCDSF/UKQCD/CSSM on the breaking in meson decay constants. The -quarks are generated with an anisotropic clover-improved action, and are tu…
The Compton Amplitude, lattice QCD and the Feynman-Hellmann approach
K. U. Can, A. Hannaford-Gunn, R. Horsley +8
A major objective of lattice QCD is the computation of hadronic matrix elements. The standard method is to use three-point and four-point correlation functions. An alternative appr…