Related papers: Systematics in nucleon matrix element calculations
Using the gradient flow, we calculated the nucleon mixing angle $\alpha_{N}$ and the nucleon electric dipole moment (EDM) induced by the QCD $\theta$-term. To do so, we computed the topological charge, and the nucleon two-point and…
I review a number of the open questions about neutrino properties, critique recent hints of neutrino mass, and discuss one recently proposed neutrino mass matrix to illustrate the direction in which we may be headed. I also present one…
A remarkably successful program of parity-violating electron scattering experiments is providing new insight into the structure of the nucleon. Measurement of the vector form factors enables a definitive study of potential strange…
The QCDSF/UKQCD collaboration has an ongoing program to calculate nucleon matrix elements with two flavours of dynamical O(a) improved Wilson fermions. Here we present recent results on the electromagnetic form factors, the quark momentum…
I give a summary of recent results on nucleon polarizabilities, with emphasis on chiral perturbation theory. The predictive calculations of Compton scattering off the nucleon are compared to recent empirical determinations and lattice QCD…
We employ leading order covariant chiral perturbation theory to compute the nucleon-pion-state contribution to the 3-point correlation functions one typically measures in lattice QCD to extract the isovector nucleon charges $g_A,g_T$ and…
The implications of chiral symmetry for the quark model are discussed. In particular its connection with the meson-baryon approach is outlined. It is stressed that in the closure approximation, where the intermediate baryon states are used…
Dyson-Schwinger equation treatments of the strong interaction show that the presence and importance of nonpointlike diquark correlations within the nucleon are a natural consequence of dynamical chiral symmetry breaking. Using this…
The matrix element technique provides a superior statistical sensitivity for precision measurements of important parameters at hadron colliders, such as the mass of the top quark or the cross section for the production of Higgs bosons. The…
One of the most challenging tasks in lattice calculations of baryon form factors is the analysis and control of excited-state contaminations. Taking the isovector axial form factors of the nucleon as an example, both a dispersive…
The existing calculations of the nuclear matrix elements of the neutrinoless double beta-decay differ by about a factor three. This uncertainty prevents quantative interpretation of the results of experiments searching for this process. We…
We seek to understand the physical significance of the nucleon's tensor charge and make estimates of its size in phenomenological models and the QCD sum rule.
We present a concise review of models for neutrino masses and mixings with particular emphasis on recent developments and current problems. We discuss in detail attempts at reproducing approximate tri-bimaximal mixing starting from discrete…
The electromagnetic form factors of the nucleon are calculated in an extended chiral constituent-quark model where the effective interaction is described by the exchange of pseudoscalar, vector, and scalar mesons. Two-body current-density…
We report on recent results for the pion and nucleon matrix element of the twist-2 operator corresponding to the average momentum of non-singlet quark densities. We discuss finite size effects for the nucleon matrix element and present…
The electromagnetic form factors of the nucleon have been calculated in a chiral constituent-quark model. The nucleon wave functions are obtained by solving a Schr\"odinger-type equation for a semi-relativistic Hamiltonian with an effective…
We consider radiative \beta--decay of the neutron in heavy baryon chiral perturbation theory, with an extension including explicit \Delta degrees of freedom. We compute the photon energy spectrum as well as the photon polarization; both…
Constructing numerical models of noisy partial differential equations is very delicate. Our long term aim is to use modern dynamical systems theory to derive discretisations of dissipative stochastic partial differential equations. As a…
I summarize the status of neutrino oscillations that follow from current data, including the status of the small parameters ratio of solar-over-atmospheric splitting and $\sin^2\theta_{13}$ characterizing the strength of CP violation in…
We present an update of our analysis of statistical and systematic errors in the calculation of iso-vector scalar, axial and tensor charges of the nucleon. The calculations are done using $N_f=2+1+1$ flavor HISQ ensembles generated by the…