Mridupawan Deka

Nucleon strangeness form factors from N(f) = 2+1 clover fermion lattice QCD

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 hopping parameter expansion. In addition to increasing the number of Z(4) noises, we find that increasing the number of nucleon sources for each configuration improves the signal significantly. We obtain G_M^s(0) = -0.017(25)(07), where the first error is statistical, and the second is the uncertainties in Q^2 and chiral extrapolations. This is consistent with experimental values, and has an order of magnitude smaller error. We also study the strangeness second moment of the partion distribution function of the nucleon, _{s-\bar{s}}.

Moments of nucleon's parton distribution for the sea and valence quarks from lattice QCD

We extend the study of lowest moments, and , of the parton distribution function of the nucleon to include those of the sea quarks; this entails a disconnected insertion calculation in lattice QCD. This is carried out on a 16{sup 3}x24 quenched lattice with Wilson fermion. The quark loops are calculated with Z{sub 2} noise vectors and unbiased subtractions, and multiple nucleon sources are employed to reduce the statistical errors. We obtain 5{sigma} signals for for the u, d, and s quarks, but is consistent with zero within errors. We provide results for both the connected and disconnected insertions. The perturbatively renormalized for the strange quark at {mu}=2 GeV is {sub s+s}=0.027{+-}0.006 which is consistent with the experimental result. The ratio of for s vs u/d in the disconnected insertion with quark loops is calculated to be 0.88{+-}0.07. This is about twice as large as the phenomenologically fitted ( {sub s+s}/ {sub u}+ {sub d}) from experiments where u and d include both the connected and disconnected insertion parts. We discuss the source and implication of this difference.

Quark and Glue Momenta and Angular Momenta in the Proton --- a Lattice Calculation

We report a complete calculation of the quark and glue momenta and angular momenta in the proton. These include the quark contributions from both the connected and disconnected insertions. The calculation is carried out on a

Metastable states in quark-gluon plasma

16^3 \times 24

Confinement-deconfinement transition in an SU(2) Higgs theory

quenched lattice at

Nucleon strangeness form factors and moments of PDF

\beta = 6.0

_{u-d} from lattice QCD at nearly physical quark masses

and for Wilson fermions with

Strangeness and glue in the nucleon from lattice QCD

\kappa = 0.154, 0.155,

The calculation of nucleon strangeness form factors from N_f=2+1 clover fermion lattice QCD

and 0.1555 which correspond to pion masses at 650, 538, and 478 MeV. The quark loops are calculated with

Nucleon strangeness form factors from N_f=2+1 clover fermion lattice

Z_4