arXiv subjects

M. Tomii

Publications and source records attributed to M. Tomii.

7 recordsLinked to original sources

arXiv2024

The long-distance window of the hadronic vacuum polarization for the muon g-2

We provide the first ab-initio calculation of the Euclidean long-distance window of the isospin symmetric light-quark connected contribution to the hadronic vacuum polarization for the muon $g-2$ and find $a_\mu^{\rm LD,iso,conn,ud} = 411.4(4.3)(2.4) \times 10^{-10}$. We also provide the currently most precise calculation of the total isospin symmetric light-quark connected contribution, $a_\mu^{\rm iso,conn,ud} = 666.2(4.3)(2.5) \times 10^{-10}$, which is more than 4$\sigma$ larger compared to the data-driven estimates of Boito et al. 2022 and 1.7$\sigma$ larger compared to the lattice QCD result of BMW20.

hep-lat↗

arXiv2017

Lattice calculation of coordinate-space vector and axial-vector current correlators in QCD

We study the vector and axial-vector current correlators in perturbative and non-perturbative regimes of QCD. The correlators in Euclidean coordinate space are calculated on the lattice using the Möbius domain-wall fermion formulation at three lattice spacings covering 0.044--0.080~fm. The dynamical quark effects of $2+1$ light flavors are included. The sum $V+A$ and the difference $V-A$ of the vector ($V$) and axial-vector ($A$) current correlators calculated on the lattice after extrapolating to the physical point agree with those converted from the ALEPH experimental data of hadronic $τ$ decays. The level of the agreement in the $V+A$ channel is about $1.3σ$ or smaller in the region of $|x|\ge0.4$~fm, while that in the $V-A$ channel is about $1.8σ$ at $|x|=0.74$~fm and smaller at other distances. We also extract the hiral condensate from the short-distance correlators on the lattice using the PCAC relation. Its result extrapolated to the chiral and continuum limit is compatible with other estimates at low energies.

hep-lat↗

arXiv2016

Renormalization of domain-wall bilinear operators with short-distance current correlators

We determine the renormalization constants for flavor non-singlet fermion bilinear operators of Möbius domain-wall fermions. The renormalization condition is imposed on the correlation functions in the coordinate space, such that the non-perturbative lattice calculation reproduces the perturbatively calculated counterpart at short distances. The perturbative expansion is precise as the coefficients are available up to $O(α_s^4)$. We employ $2+1$-flavor lattice ensembles at three lattice spacings in the range 0.044--0.080~fm.

hep-lat↗

arXiv2015

Decay constants and spectroscopy of mesons in lattice QCD using domain-wall fermions

We report results of masses and decay constants of light and charmed pseudo-scalar mesons using lattice QCD with Möbius domain-wall fermions. Using this formulation we are able to compute pseudo-scalar decay constants through the pseudo-scalar density operator as well as with the axial-vector current. Results are shown from several lattice spacings and pion masses between 230 MeV and 500 MeV. We present an analysis of these results at different quark masses to show the chiral properties of the light mesons masses and decay constants.

hep-lat↗

arXiv2015

Analysis of short-distance current correlators using OPE

We investigate the correlators of flavor non-singlet bilinear operators calculated on the lattice at short distances. In the continuum theory, non-perturbative effects are encoded in the form of the operator product expansion (OPE). We test the prediction of OPE by comparing lattice results with those in the continuum theory. We also determine the renormalization factors of quark currents.

hep-lat↗

arXiv2014

Non-perturbative renormalization of bilinear operators with Möbius domain-wall fermions in the coordinate space

We study the non-perturbative determination of the renormalization constants of flavor non-singlet quark bilinear operators on the lattice. The renormalization condition is imposed on correlation functions of bilinear operators in the coordinate space. The results are converted to the value at 2 GeV in the $\rm\overline{MS}$ scheme by a perturbative matching. The calculation is carried out on gauge configurations generated with the Mobius domain-wall fermions at two lattice spacings $a^{-1} = 2.4$ GeV and $a^{-1} = 3.6$ GeV.

hep-lat↗

arXiv2013

Lattice Study on quantum-mechanical dynamics of two-color QCD with six light flavors

We investigate the chiral properties of SU(2) gauge theory with six flavors, i.e. six light Dirac fermions in the fundamental representations by lattice simulation, and point out that the spontaneous breakdown of chiral symmetry does not occur in this system. The quark mass dependence of the mesonic spectrum provides an evidence for such a possibility. The decay constant tends to be increased by the finite size effect, which is opposite to the behavior predicted by chiral perturbation theory and indicates that the long distance dynamics in the six-flavor theory could be different from the theory with chiral symmetry breaking. The subtracted chiral condensate, whose utility is demonstrated by the simulation of two-flavor theory, is shown to vanish in the chiral limit within the precision of available data.

hep-lat↗