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Yasumichi Aoki

Publications and source records attributed to Yasumichi Aoki.

82 records · Page 5Linked to original sources
arXiv2009

Quark mass renormalization with non-exceptional momenta

Renormalization conditions imposed on quark bilinear vertex functions in the conventional RI/MOM scheme use exceptional momentum configurations. With practical values for the lattice cutoff, these vertex functions are contaminated with unwanted low energy physics (pion pole, zero modes, etc), which is a large source of systematic error. These effects can be reduced by using non-exceptional momenta. We discuss the quark mass renormalization with non-exceptional momenta using 2+1 flavor domain wall fermions based on a recently proposed RI/SMOM scheme.

hep-lat↗
arXiv2007

QCD finite T transition -- Comparison between Wilson and staggered results

A quantitative comparison between the finite temperature behaviour of the staggered and Wilson fermion formulations are performed. The comparison is based on a physical quantity that is expected to be quite sensitive to the fermionic features of the action. For that purpose we use the height of the peak for $dχ_s/dT$, where $χ_s$ is the quark number susceptibility.

hep-lat↗
arXiv2004

Nucleon Decay Matrix Elements with N_f=0 and 2 Domain-Wall Quarks

The nucleon decay matrix elements of three-quark operators are calculated with domain-wall fermions. Operators are renormalized non-perturbatively to match the MS bar (NDR) scheme at NLO. Quenched simulation studies involve both direct measurement of the matrix elements and the chiral Lagrangian parameters, alpha and beta. We also report on the dynamical quark effects on these parameters.

hep-lat↗
arXiv2003

Nucleon Decay with Domain-Wall Fermions

We report on our on-going project to calculate the nucleon decay matrix elements with domain-wall fermions. Operator mixing is discussed employing a non-perturbative renormalization. Bare matrix elements of all the possible decay modes induced by the dimension-six operators are calculated with the direct method, which are compared with the indirect calculation using chiral perturbation theory.

hep-lat↗
arXiv2003

Hadronic matrix elements of proton decay on the lattice

We report on our on-going project to calculate proton decay matrix elements using domain-wall fermions on the lattice. By summarizing the history of the proton decay calculation on the lattice, we reveal the systematic errors of those calculations. Then we discuss our approach to tackle those uncertainties and show our preliminary results on the matrix elements.

hep-lat↗
arXiv2002

Nucleon Decay Matrix Elements for Domain-Wall Fermions

We report on the nucleon decay matrix elements with domain-wall fermions in quenched approximation. Results from direct and indirect method are compared with a focus on the process of a proton decaying to a pion and a lepton. We discuss the renormalization necessary for the matching to the continuum theory. Preliminary results for the renormalized chiral lagrangian parameters are presented.

hep-lat↗
arXiv1997

Four-dimensional Simulation of the Hot Electroweak Phase Transition with the SU(2) Gauge-Higgs Model

We study the finite-temperature electroweak phase transition of the minimal standard model within the four-dimensional SU(2) gauge-Higgs model. Monte Carlo simulations are performed for intermediate values of the Higgs boson mass in the range $50 \lesssim M_H \lesssim 100$GeV on a lattice with the temporal size $N_t=2$. The order of the transition is systematically examined using finite-size scaling methods. Behavior of the interface tension and the latent heat for an increasing Higgs boson mass is also investigated. Our results suggest that the first-order transition terminates around $M_H \sim 80$GeV.

hep-lat↗
arXiv1996

Four-dimensional Simulation of the Hot Electroweak Phase Transition with the SU(2) Gauge-Higgs Model

We study the finite-temperature phase transition of the four-dimensional SU(2) gauge-Higgs model for intermediate values of the Higgs boson mass in the range $50 \lsim m_H \lsim 100$GeV on a lattice with the temporal lattice size $N_t=2$. The order of the transition is systematically examined using finite size scaling methods. Behavior of the interface tension and the latent heat for an increasing Higgs boson mass is also investigated.

hep-lat↗
arXiv1993

Interface tension in SU(3) lattice gauge theory at finite temperatures on an $N_t=2$ lattice

The surface tension $σ$ of the confined-deconfined interface is calculated in pure $SU(3)$ lattice gauge theory at finite temperatures employing the operator and integral methods on a lattice of a size $8^2\times N_z\times 2$ with $N_z=16$ and 40. Analyses of non-perturbative corrections in asymmetry response functions strongly indicate that the use of one-loop values for the response functions lead to an overestimate of $σ$ in the operator method. The operator method also suffers more from finite-size effects due to a finite thickness of the interface, leading us to conclude that the integral method yields more reliable values for $σ$. Our result with the integral method $σ/T_c^3=0.134(16)$ is consistent with earlier results and also with that obtained with a transfer matrix method. Result is also reported on $σ$ obtained on a lattice $18^2\times 48\times 4$ with the integral method.

hep-lat↗