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We study the strangeness contribution to nucleon matrix elements using Nf=2+1 dynamical clover fermion configurations generated by the CP-PACS/JLQCD collaboration. In order to evaluate the disconnected insertion (DI), we use the Z(4) stochastic method, along with unbiased subtraction from the hopping parameter expansion which reduces the off-diagonal noises in the stochastic method. Furthermore, we find that using many nucleon sources for each configuration is effective in improving the signal. Our results for the quark contribution to the first moment <x>_q in the DI, and the strangeness magnetic moment show that the statistical errors are under control with these techniques. We also study the gluonic contribution to the nucleon using the overlap operator to construct the gauge field tensor, F_{mu,nu}. The application to the calculation of first moment, <x>_G, gives a good signal in quenched lattice QCD.
By introducing an additional operator into the action and using the Feynman-Hellmann theorem we describe a method to determine both the quark line connected and disconnected terms of matrix elements. As an illustration of the method we calculate the
We study the strangeness electromagnetic form factors of the nucleon from the N_f=2+1 clover fermion lattice QCD calculation. The disconnected insertions are evaluated using the Z(4) stochastic method, along with unbiased subtractions from the hoppin
We study the KN interactions in the I(J^{pi})=0(1/2^-) and 1(1/2^-) channels and associated exotic state Theta^+ from 2+1 flavor full lattice QCD simulation for relatively heavy quark mass corresponding to m_{pi}=871 MeV. The s-wave KN potentials are
We calculate $pXi^0$ potentials from the equal-time Bethe-Salpeter amplitude measured in the quenched QCD simulation with the spatial lattice volume, (4.4 fm)$^3$. The standard Wilson gauge action with the gauge coupling $beta=5.7$ on $32^4$ lattice
We present a new analysis method that allows one to understand and model excited state contributions in observables that are dominated by a pion pole. We apply this method to extract axial and (induced) pseudoscalar nucleon isovector form factors, wh