Computing Group

The computing group founded in 2011 as a part of of the RIKEN BNL Research Center established at Brookhaven National Laboratory in New York, USA, and dedicated to conduct researches and devlopements for large scale physics computations important for particle and nuclear theory.
The main subjects include the lattice gauge theory, such as lattice QCD describing the sub-atomic structures of hadrons, which allow us the ab-initio investigation for strongly interacting quantum field theories beyond pertrubative analysis. The three of the major activities are R&D for high performance computers, developments for computing algorithms, and researches of particle, nuclear, and lattice theories.

In 1997, the group pioneered the use of the domain-wall fermions, which preserve chiral symmetry, a key symmetry for understainding nature of paritcle nuclear physics, and investigate various hadron physics including an important calculation of quark flavor mixing and CP-violations that is relevant for checking the standard model of particle nuclear physics utilizing the Cabibbo-Kobayashi-Maskawa theory.

In JFY2004, the numerical lattice QCD group built a 10 TFlops QCDOC parallel supercomputer dedicated for the first-principle non-perturbative calculations of QCD. A total 600 teraflop (peak) successor to the QCDOC computer, three racks of QCDCQ (QCD with Chiral Quarks), is installed and starts to run new physics programs.

Research Subjects

• High performance computers for particle nuclear physics
• Algorithms for computings in particle nuclear physcs
• Particle, Nuclear, and lattice field theories

Publications

1. T. Yamazaki et al.:
   "Nucleon axial charge in 2+1 flavor dynamical lattice QCD with domain wall fermions"
   Phys. Rev. Lett. 100:171602, 2008.
2. Thomas Blum, Takumi Doi, Masashi Hayakawa, Taku Izubuchi, Norikazu Yamada:
   "Determination of light quark masses from the electromagnetic splitting of pseudoscalar meson masses computed with two flavors of domain wall fermions"
   Phys.Rev.D76:114508,2007.
3. T. Blum, R. Zhou , T. Doi , M. Hayakawa, T. Izubuchi, S. Uno, N. Yamada:
   "Electromagnetic mass splittings of the low lying hadrons and quark masses from 2+1 flavor lattice QCD+QED."
   Phys.Rev. D82 (2010) 094508
4. T. Blum, P.A. Boyle, N.H. Christ, N. Garron, E. Goode, T. Izubuchi, C. Jung, C. Kelly, C. Lehner, M. Lightman et al.:
   "The K→(ππ)I=2 Decay Amplitude from Lattice QCD"
   Phys. Rev. Lett. (2012)
5. Noriyoshi Ishii, Sinya Aoki, Tetsuo Hatsuda:
   "The Nuclear Force from Lattice QCD"
   Phys.Rev.Lett.99:022001,2007.
6. Y. Aoki et al.:
   "The QCD transition temperature: results with physical masses in the continuum limit II"
   JHEP 0906:088,2009.
7. M. Cheng et al.:
   "The QCD Equation of State with almost Physical Quark Masses"
   Phys. Rev. D77: 014511, 2008.
8. T. Blum , P.A. Boyle, N.H. Christ, N. Garron, E. Goode, T. Izubuchi, C. Lehner, Q. Liu, R.D. Mawhinney, C.T. Sachrajda et al.:
   "K to ππ Decay amplitudes from Lattice QCD"
   Phys.Rev. D84 (2011) 114503
9. D.J. Antonio, et al.:
   "Neutral kaon mixing from 2+1 flavor domain wall QCD"
   Phys.Rev.Lett.100:032001,2008.
10. C. Allton et al.:
    "Physical Results from 2+1 Flavor Domain Wall QCD and SU(2) Chiral Perturbation Theory"
    Phys. Rev. D78: 114509, 2008.