Thermal Width Broadening of the 0++ Glueball Spectrum near Tc

We study the 0++ glueball correlator constructed with SU(3) anisotropic quenched lattice QCD at various temperature taking into account the possible existence of the thermal width in the ground-state peak. For this purpose, we adopt the Breit-Wigner ansatz, analysing the lattice data obtained with 5,500-9,900 gauge configurations at each T. The results indicate the significant thermal width broadening as Gamma(Tc) \sim 300 MeV with a reduction in the peak center as Delta omega_0(Tc) \sim 100 MeV in the vicinity of the critical temperature Tc.Comment: Talk given at Tokyo-Adelaide Joint Workshop on Quarks, Astrophysics and Space Physics, Tokyo, Japan, 6-10 January 2003, 5 pages, Latex2e, 2 figure

Glueball properties in anisotropic SU(3) lattice QCD with improved action

We study the glueballs properties at finite temperature using SU(3) lattice QCD at the quenched level with the anisotropic lattice. We use the tree-level Symanzik O(a^2) improved action. We present our preliminary results which shows the slight reduction of the scalar glueball mass near T_cComment: 8 pages, 13 figures, Talk given at Joint Workshop of the Special Research Center for the Subatomic Structure of Matter and the National Institute for Theoretical Physics (Workshop on Lepton Scattering, Hadrons and QCD), Adelaide, Australia 26 March - 6 April 200

Wilson and Domainwall Kernels on Oakforest-PACS

We report the performance of Wilson and Domainwall Kernels on a new Intel Xeon Phi Knights Landing based machine named Oakforest-PACS, which is co-hosted by University of Tokyo and Tsukuba University and is currently fastest in Japan. This machine uses Intel Omni-Path for the internode network. We compare performance with several types of implementation including that makes use of the Grid library. The code is incorporated with the code set Bridge++.Comment: 8 pages, 9 figures, Proceedings for the 35th International Symposium on Lattice Field Theory (Lattice 2017

Practical Implementation of Lattice QCD Simulation on Intel Xeon Phi Knights Landing

We investigate implementation of lattice Quantum Chromodynamics (QCD) code on the Intel Xeon Phi Knights Landing (KNL). The most time consuming part of the numerical simulations of lattice QCD is a solver of linear equation for a large sparse matrix that represents the strong interaction among quarks. To establish widely applicable prescriptions, we examine rather general methods for the SIMD architecture of KNL, such as using intrinsics and manual prefetching, to the matrix multiplication and iterative solver algorithms. Based on the performance measured on the Oakforest-PACS system, we discuss the performance tuning on KNL as well as the code design for facilitating such tuning on SIMD architecture and massively parallel machines.Comment: 8 pages, 12 figures. Talk given at LHAM'17 "5th International Workshop on Legacy HPC Application Migration" in CANDAR'17 "The Fifth International Symposium on Computing and Networking" and to appear in the proceeding

Charmonium at finite temperature in quenched lattice QCD

We study charmonium correlators in pseudoscalar and vector channels at finite temperature using lattice QCD simulation in the quenched approximation. Anisotropic lattices are used in order to have sufficient numbers of degrees of freedom in the Euclidean temporal direction. We focus on the low energy structure of the spectral function, corresponding to the ground state in the hadron phase, by applying the smearing technique to enhance the contribution to the correlator from this region. We employ two analysis procedures: the maximum entropy method (MEM) for the extraction of the spectral function without assuming a specific form, to estimate the shape of the spectral function, and the standard $\chi^2$ fit analysis using typical forms in accordance with the result of MEM, for a more quantitative evaluation. To verify the applicability of the procedures, we first analyze the smeared correlators as well as the point correlators at zero temperature. We find that by shortening the $t$-interval used for the analysis (a situation inevitable at $T>0$) the reliability of MEM for point correlators is lost, while it subsists for smeared correlators. Then the smeared correlators at $T\simeq 0.9 T_c$ and $1.1 T_c$ are analyzed. At $T\simeq 0.9 T_c$, the spectral function exhibits a strong peak, well approximated by a delta function corresponding to the ground state with almost the same mass as at T=0. At $T\simeq 1.1 T_c$, we find that the strong peak structure still persists at almost the same place as below $T_c$, but with a finite width of a few hundred MeV. This result indicates that the correlators possess a nontrivial structure even in the deconfined phase.Comment: 19 pages, 26 figure