Keitaro Nagata

Wilson fermion determinant in lattice QCD

We present a formula for reducing the rank of Wilson fermions from 4N{sub c}N{sub x}N{sub y}N{sub z}N{sub t} to 4N{sub c}N{sub x}N{sub y}N{sub z} keeping the value of its determinant. We analyze eigenvalues of a reduced matrix and coefficients C{sub n} in the fugacity expansion of the fermion determinant nC{sub n}(exp({mu}/T)){sup n}, which play an important role in the canonical formulation, using lattice QCD configurations on a 4{sup 4} lattice. Numerically, log|C{sub n}| varies as N{sub x}N{sub y}N{sub z}, and goes easily over the standard numerical range. We give a simple cure for that. The phase of C{sub n} correlates with the distribution of the Polyakov loop in the complex plain. These results lay the groundwork for future finite density calculations in lattice QCD.

Chiral properties of baryon fields with flavor SU(3) symmetry

We investigate chiral properties of local (nonderivative) fields of baryons consisting of three quarks with flavor SU(3) symmetry. We construct explicitly independent local three-quark fields belonging to definite Lorentz and flavor representations. Chiral symmetry is spontaneously broken and therefore the baryon fields can have different chiral representations. Because of the color antisymmetric and spatially symmetric structure of the local three-quark fields, the allowed chiral representations are strongly correlated with the Lorentz group representations. We discuss some implications of the allowed chiral symmetry representations on physical quantities such as the axial coupling constants.

Imaginary chemical potential approach for the pseudocritical line in the QCD phase diagram with clover-improved Wilson fermions

The QCD phase diagram is studied in the lattice QCD simulation with the imaginary chemical potential approach. We employ a clover-improved Wilson fermion action of two-flavors and a renormalization-group improved gauge action, and perform the simulation at an intermediate quark mass on a

CHIRAL PROPERTIES OF BARYON INTERPOLATING FIELDS

8^3\times 4

EoS of finite density QCD with Wilson fermions by multi-parameter reweighting and Taylor expansion

lattice. The QCD phase diagram in the imaginary chemical potential

Two-boson exchange corrections to parity-violating elastic electron-proton scattering

\mu_I

Contribution of two-boson exchange with Δ(1232) excitation to parity-violating elastic electron-proton scattering

region is investigated by performing the simulation for more than 150 points on the

Two nucleon states in a chiral quark-diquark model

(\beta,\mu_I)

NUCLEON AXIAL COUPLINGS AND [(½,0) ⊕ (0,½)]-[(1,½) ⊕ (½,1)] CHIRAL MULTIPLET MIXING

plane. We find that the Roberge-Weiss phase transition at

piN and pipiN couplings of the Delta(1232) and its chiral partners.

\mu_I/T=\pi/3