相关论文: Lattice Results on the Connected Neutron Charge Ra…
The nuclear charge radius of $^{32}$Si was determined using collinear laser spectroscopy. The experimental result was confronted with ab initio nuclear lattice effective field theory, valence-space in-medium similarity renormalization…
I present an overview of the calculations of the isovector axial vector form factor of the nucleon, $G_A(Q^2)$, using lattice QCD. Based on a comparison of results from various collaborations, a case is made that lattice results are now…
We determine the root-mean-square proton charge radius, $R_{\rm p}$, from a fit to low-$Q^2$ electron-proton elastic scattering cross section data with the higher moments fixed (within uncertainties) to the values predicted by chiral…
The possibility of the determination of the neutron mean square charge radius from high-precision thermal-neutron measurements of the nuclear scattering length and of the scattering amplitudes of Bragg reflections is considered. Making use…
We compute the electromagnetic form factors of the nucleon in quenched lattice QCD, using non-perturbatively improved Wilson fermions, and compare the results with phenomenology and chiral effective field theory.
First results of lattice QCD simulation on the nucleon tensor-charge $\delta q$ are presented. From the quenched QCD simulations with the Wilson quark action at $\beta = 5.7$ on a 16$^3\times$ 20 lattice and on a $12^3\times 20$ lattice, we…
We review determinations of the electric proton charge radius from a diverse set of low-energy observables. We explore under which conditions it can be related to Wilson coefficients of appropriate effective field theories. This discussion…
We evaluate the neutron electric dipole moment $\vert \vec{d}_N\vert$ using lattice QCD techniques. The gauge configurations analyzed are produced by the European Twisted Mass Collaboration using $N_f{=}2{+}1{+}1$ twisted mass fermions at…
We describe a procedure for extracting momentum derivatives of nucleon matrix elements on the lattice directly at $Q^2=0$. This is based on the Rome method for computing momentum derivatives of quark propagators. We apply this procedure to…
We extract the neutron charge form factor from the charge form factor of deuteron obtained from $T_{20}(Q^2)$ data at $0\le Q^2\le$ 1.717 (GeV$^2$). The extraction is based on the relativistic impulse approximation in the instant form of…
The charge radius is one of the most basic characteristics of the nucleons. The proton charge radius is especially of great importance for many applications such as the structure studies of the atomic nuclei, the determination of the…
The outcome of the SAMPLE Experiment suggests that the strange-quark contribution to the nucleon magnetic moment, G_M^s(0), may be greater than zero. This result is very difficult to reconcile with expectations based on the successful…
The neutron is electrically neutral, but its substructure consists of charged quarks so it may have an internal charge distribution. In fact it is known to have a negative mean square charge radius (MSCR), the second moment of the radial…
Point-to-point vacuum correlation functions for spatially separated hadron currents are calculated in quenched lattice QCD on a $16^3\times 24$ lattice with $6/g^2=5.7$. The lattice data are analyzed in terms of dispersion relations, which…
We present the first lattice-QCD result for the Zemach and Friar radii of the proton and neutron. Our calculation includes both quark-connected and -disconnected diagrams and assesses all sources of systematic uncertainties arising from…
There has been much progress in the experimental measurement of the electric and magnetic polarizabilities of the nucleon. Similarly, lattice QCD simulations have recently produced dynamical QCD results for the magnetic polarizability of…
In our previous DWF calculation with the Wilson gauge action at $\beta=6.0$ ($a^{-1}\simeq$ 1.9 GeV) on a $16^3 \times 32 \times 16$ lattice, we found that $\Ga$ had a fairly strong dependence on the quark mass. A simple linear…
We present a high-accuracy calculation of the deuteron structure radius in chiral effective field theory. Our analysis employs the state-of-the-art semilocal two-nucleon potentials and takes into account two-body contributions to the charge…
We present the current status of our lattice calculation of the electromagnetic form factor of the pion with two flavours of non-perturbatively O(a)-improved Wilson fermions. Using twisted boundary conditions and stochastic sources we…
We discuss the experimental data on the n,e-scattering length bne and the values of mean square charge radius of the neutron <r^2> obtained from them. It is shown that the accumulated during the last 50 years most significant experimental…