Related papers: Connected and disconnected quark contributions to …
We propose a new model for describing baryon semi-leptonic decays for estimating $F$ and $D$ values with explicit breaking effects of both SU(3) and SU(2) flavor symmetry, where all possible SU(3) and SU(2) breaking effects are induced from…
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 energy term, the glue energy term and the trace anomaly…
We present results of quenched $SU(3)$ hadron spectroscopy using $\order(a)$ improved Wilson fermions. The configurations were generated using an $\order(a^2)$ improved 6-link $SU(3)$ pure gauge action at $\beta$'s corresponding to lattice…
Using iso-spin symmetry the quark-connected and disconnected contributions to the hadronic vacuum polarisation in a theory with N_f=2 flavours can be described as independent correlation functions, respectively. We show how this allows to…
By considering a flavour expansion about the SU(3)-flavour symmetric point, we investigate how flavour-blindness constrains octet baryon matrix elements after SU(3) is broken by the mass difference between the strange and light quarks. We…
Hadron spectroscopy is revealed by observing heavy resonances. Among various explanations of the internal structure of these hadronic states, hadronic molecules play a unique role. For hadronic molecules, which are associated with…
In this work, we explore new spin-1 states with axial couplings to the standard model fermions. We develop a data-driven method to estimate their hadronic decay rates based on data from $\tau$ decays and using SU(3)$_{\rm flavor}$ symmetry.…
We present a general formalism for simplifying manipulations of spin indices of massless and massive spinors and vectors in Feynman diagrams. The formalism is based on covariantly reducing the number of field components in the action in…
We analyse the twist-three amplitudes that can give rise to single-spin asymmetries in hadron-hadron scattering; in so doing we bring to light a novel factorisation property. As already known, the requirement of an imaginary part leads to…
The exact form factor for the O(3) non-linear sigma model is used to predict the three-magnon contribution to the spin correlation function, S(q,w), near wavevector q=pi in an integer spin, one-dimensional antiferromagnet. The three-magnon…
The role of nonvalence, {\it e.g.} sea quarks and/or meson degrees of freedom in static and quasistatic baryon electroweak observables, is discussed within the phenomenological sum rule approach. The inclusion of nonvalence degrees of…
In recent lattice QCD studies, the Feynman-Hellmann theorem is often used to estimate separate contributions of the connected and disconnected diagrams to the nucleon sigma term. We demonstrate through a simple analysis within an effective…
We show that three-quark axial currents as required by broken SU(6) spin-flavor symmetry reduce the quark spin contribution to proton spin from $\Sigma_p = 1$ (one-quark axial current value) to $\Sigma_p = 0.41(12)$ consistent with the…
We show that hadronic matrix elements can be extracted from lattice simulations with background fields that arise from operator exponentiation. Importantly, flavour-singlet matrix elements can be evaluated without requiring the computation…
The contributions from the $qqqq\bar q$ components to the magnetic moments of the octet as well as the $\Delta^{++}$ and $\Omega^-$ decuplet baryons are calculated for the configurations that are expected to have the lowest energy if the…
We report a quark spin calculation from the anomalous Ward identity with overlap fermions on 2+1 flavor dynamical fermion configurations with light sea quark masses. Such a formulation decomposes the divergence of the flavor-singlet…
We compute the hadronic matrix elements of the four-quark operators needed for the study of neutral kaon mixing beyond the Standard Model (SM). We use nf=2+1 flavours of domain-wall fermions (DWF) which exhibit good chiral-flavour symmetry.…
We report progress on calculating the contribution to the anomalous magnetic moment of the muon from the disconnected hadronic diagrams with light and strange quarks and the valence QED contribution to the connected diagrams. The lattice…
A topological interpretation of the electron--electron interaction under FQHE conditions gives rise to the existence of some kind of composite fermions. The interaction term is similar to the Coulomb interaction and produces punctures in…
We demonstrate that formulating the composite-fermion theory of the fractional quantum Hall (FQH) effect in terms of quaternions greatly expands its reach and opens the door into many interesting issues that were previously beyond the reach…