相关论文: Lattice Results on the Connected Neutron Charge Ra…
This document is one of a series of whitepapers from the USQCD collaboration. Here, we discuss opportunities for lattice QCD in neutrino-oscillation physics, which inevitably entails nucleon and nuclear structure. In addition to discussing…
We propose to extract the value of the effective neutrino charge radius from the coherent scattering of a neutrino against a heavy nucleus. In such an experiment the relevant quantity to measure is the kinetic energy distribution of the…
We present a new lattice formulation of chiral effective field theory interactions with a simpler decomposition into spin channels. With these interactions the process of fitting to the empirical scattering phase shifts is simplified, and…
We study nuclear and neutron matter by combining chiral effective field theory with non-perturbative lattice methods. In our approach nucleons and pions are treated as point particles on a lattice. This allows us to probe larger volumes,…
We give a brief overview of recent progress in lattice QCD simulations that is enabling precision studies of the three-dimensional structure of the nucleon. We present results on nucleon charges and second Mellin moments of parton…
We present a determination of the pion charge radius from high precision data on the pion vector form factor from both timelike and spacelike regions, using a novel formalism based on analyticity and unitarity. At low energies, instead of…
We report on our calculation of the nucleon axial charge gA in QCD with two flavours of dynamical quarks. A detailed investigation of systematic errors is performed, with a particular focus on contributions from excited states to…
We present the strange electromagnetic form factors of the nucleon using lattice QCD with $N_f=2+1+1$ twisted mass clover-improved fermions and quark masses tuned to their physical values. Using four ensembles with lattice spacings of…
The root-mean-square (rms) nuclear charge radius of ^8He, the most neutron-rich of all particle-stable nuclei, has been determined for the first time to be 1.93(3) fm. In addition, the rms charge radius of ^6He was measured to be 2.068(11)…
Flagship neutrino oscillation experiments depend on precise and accurate theoretical knowledge of neutrino-nucleon cross sections across a variety of energies and interaction mechanisms. Key ingredients to the amplitudes that make up these…
Lattice QCD calculations of two-nucleon systems are used to isolate the short-distance two-body electromagnetic contributions to the radiative capture process $np \to d\gamma$, and the photo-disintegration processes $\gamma^{(\ast)} d \to…
Protons are bound states of the strong interaction governed by Quantum Chromodynamics (QCD). Its charge radius ($r_{E}^{p}$) is an important quantity as it characterizes the spatial distribution of the proton's charge, which is carried by…
The deuteron charge radius is calculated from the measurement of the Lamb shift in muonic deuterium, taking into account the electron vacuum polarization correction to the nuclear-structure effects. This correction is unexpectedly large and…
Charge symmetry breaking contributions to the proton's neutral weak form factors must be understood in order for future measurements of parity violating electron-proton scattering to be definitively interpreted as evidence of proton…
A review of neutron form factor measurements is given. We focus on recent measurements of the neutron magnetic form factor $G_M^n$, and discuss in detail our measurements of this quantity at momentum transfers Q^2=0.1-0.6 (GeV/c)^2.
We present a quenched lattice QCD calculation of the first few moments of the polarized and un-polarized structure functions of the nucleon. Our calculations are done using domain wall fermions and the DBW2 gauge action with inverse lattice…
We argue that the proton charge radius conundrum can be resolved by weakening the assumption of perturbative formulation of quantum electrodynamics within the proton
We present a brief summary of recent results concerning the unambiguous definition and experimental extraction of the gauge-invariant and process-independent neutrino charge radius.
The calculation of the masses of the lightest nucleon resonances using lattice QCD is surveyed. Recent results for the mass of the first radial excitation of the nucleon, the Roper resonance, are reviewed and the interpretation in terms of…
Physical contribution of the high-energy part of hadronic spectrum is incorporated to describe the short-distance part of the correlator of heavy-quark currents obtained by quenched Monte-Carlo on a $8^3*16$- and $16^3*32$-lattices for…